Unit 1 Introduction to Chemistry Grade 7.pptx

Introduction to Chemistry Mr. Christopherson Normal Community High School www.unit5.org/chemistry

Believe that life is worth living, and your belief will help create the fact. William James, 1842-1910 American Psychologist and Philospher Whether you believe you can do a thing or believe you can’t, you are right. Henry Ford, 1863-1947 American Car Manufacturer All through my life, the new sights of Nature made me rejoice like a child. Marie Curie, 1867-1934 Polish-Born French Chemist Problems call forth our courage and our wisdom; indeed, they create our courage and our wisdom. it is only because of problems that we grow mentally and spiritually. It is through the pain of confronting and resolving problems that we learn. M. Scott Peck, b. 1936 American Psychiatrist and Writer Don’t be afraid to take a big step if one is indicated. You can’t cross a chasm in two small jumps. David Lloyd George, 1863-1945 British Prime Minister and Statesman

Chemistry is the study of matter and the transformations it can undergo…

…Matter is anything that occupies space.

…Matter is anything that occupies space. Chemistry with a Purpose

Li 3 H 1 He 2 C 6 N 7 O 8 F 9 Ne 10 Na 11 B 5 Be 4 H 1 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Rf 104 Db 105 Sg 106 Bh 107 Hs 108 Mt 109 Mg 12 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm 100 Md 101 No 102 Lr 103 La 57 Ac 89 1 2 3 4 5 6 7 * W N 7 C 6 H 1 S 16 Ir 77 O 8 N 7 Mn 25 e < The Human Element Interactive Periodic Table

Natural Science Physical Science Earth and Space Science Life Science Physics Chemistry Geology Astronomy Botany Zoology Meteorology Oceanography Ecology Genetics Natural science covers a very broad range of knowledge. Wysession, Frank, Yancopoulos, Physical Science Concepts in Action , 2004, page 4

Table of Contents ‘Introduction to Chemistry’ Introduction / Perceptions (17 slides) Safety (21 slides) Pure vs. Applied Science (10 slides) Scientific Method (27 slides) Lab Equipment (6 slides) Alchemy vs. Chemistry (30 slides) Manipulating Numerical Data (11 slides) Conversion Factors and Unit Cancellation (6 slides) Simple Math with Conversion Factors (8 slides) Scientific Notation (18 slides) Using the Exponent Key (17 slides) Basic Concepts in Chemistry (7 slides) Metric System (10 slides) Measurement (23 slides) Essential Math (14 slides)

Lecture Outline – Intro. to Chemistry Keys Lecture Outline – Introduction to Chemistry Lecture Outline – Introduction to Chemistry student notes outline textbook questions http://www.unit5.org/chemistry/intro.html textbook questions

Episode 1 – World of Chemistry VIDEO ON DEMAND The world of chemistry is introduced by providing highlights of key sequences and themes from programs in the series. The relationships of chemistry to the other sciences and to everyday life are presented. World of Chemistry The Annenberg Film Series

A Lost Child Keeping Warm Once upon a time a small child became lost. Because the weather was cold, he decided to gather material for a fire . As he brought objects back to his campfire, he discovered that some of them burned and some of them didn’t burn. To avoid collecting useless substances, the child began to keep track of those objects that burned and those that did not. This procedure if one of the elementary logical thought processes by which information is systematized. It is called inductive reasoning ( a general rule is framed on the basis of a collection of individual observations (or facts)). He proposed a possible “generalization.” Perhaps: “ Cylindrical objects burn .” Jaffe, New World of Chemistry , 1955, page 3-4

“Cylindrical Objects Burn” WILL BURN Tree limbs Broom handles Pencils Chair legs Flagpoles WON’T BURN Rocks Blackberries Marbles Paperweights Jaffe, New World of Chemistry , 1955, page 3-4

Using his generalization, the boy gathered more substances to burn. He collected three pieces of pipe, two ginger ale bottles, and the axle from an old car, while leaving a huge cardboard box full of newspapers. During the long cold night that followed he drew these conclusions : (1) The cylindrical shape of a burnable object may not be intimately associated with its flammability after all . (2) Even though the “cylindrical” rule is no longer useful, tree limbs, broom handles, pencils, and other burnables still burn . (3) He’d better bring the list along tomorrow. New idea: Perhaps “ Wooden objects burn .” Jaffe, New World of Chemistry , 1955, page 3-4

The Six Levels of Thought Knowledge Comprehension Application Analysis Synthesis Evaluation “Success is a journey, not a destination.” -Ben Sweetland “Successful students make mistakes, but they don’t quit. They learn from them.” -Ralph Burns “Success consist of a series of little daily efforts.” -Marie McCuillough

Food Elements Removed from the soil by various plants Corn Hay Wheat Cotton Oats Potatoes Tobacco 30 20 10 Pounds Per Acre Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur Jaffe, New World of Chemistry , 1955, page 468

Table: Soybean nutrient requirements in pounds/40 bushels Nutrient Seed Plant Total Nitrogen (N) 150 30 180 Phosphorus (P 2 O 5 ) 35 10 45 Potassium (K 2 O) 57 52 109 Calcium (Ca) 7 -- 7 Magnesium (Mg) 7 -- 7 Sulfur (S) 4 -- 4 Zinc (Zn) 0.04 -- 0.04 Iron (Fe) -- -- 1.20 Manganese (Mn) 0.05 -- 0.05 Copper (Cu) 0.04 -- 0.04 Molybdenum (Mo) -- -- 0.008 Most nutrients are obtained from residual sources http://www.vaes.vt.edu/tidewater/soybean/soyproduction/soyguide.html#L4 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 Strongly acid Strongly alkaline Medium acid Slightly acid Very Slightly acid Very Slightly alkaline Slightly alkaline Medium alkaline Acidity / Alkalinity (pH)

Job Skills for the Future Evaluate and Analyze Think Critically Solve Math Problems Organize and Use References Synthesize Ideas Apply Ideas to New Areas Be Creative Make Decisions with Incomplete Information Communicate in Many Modes Chemistry will develop ALL of these skills in YOU!

You’ve Finally Met Your Match

A Description of a Burning Candle A photograph of a burning candle is shown 1 in the upper right corner. The candle is cylindrical 2 and has a diameter 3 of about 3 cm. The length of the candle was initially about 16 centimeters 4 , and it changed slowly 5 during observation, decreasing about 1 cm in one hour 6 . The candle is made of a translucent 7 , white 8 solid 9 which has a slight odor 10 and no taste 11 . It is soft enough to be scratched with the fingernail 12 . There is a wick 13 which extends from top to bottom 14 of the candle along its central axis 15 and protrudes about 5 mm above the top of the candle 16 . The wick is made of three strands of string braided together 17 . A candle is lit by holding a source of flame close to the wick for a few seconds. Thereafter the source of flame can be removed and the flame sustains itself at the wick 18 . The burning candle makes no sound 19 . While burning, the body of the candle remains cool to the touch 20 except near the top. Within about 1.5 cm of the top the candle is warm 21 (but not hot) and sufficiently soft to mold easily 22 . The flame flickers in response to air currents 23 and tends to become quite smoky while flickering 24 . In the absence of air currents, the flame is of the form shown in the photograph, though it retains some movement at all times 25 . The flame begins about 2 mm above the top of the candle 26 , and at its base the flame has a blue tint 27 . Immediately around the wick in a region about 2 mm wide and extending about 5 mm above the top of the wick 28 the flame is dark 29 . This dark region is roughly conical in shape 30 . Around this zone and extending about 1 cm above the dark zone is a region which emits yellow light 31 , bright but not blinding 32 . The flame has rather sharply defined sides 33 but a ragged top 34 . The wick is white where it emerges from the candle 35 , but from the base of the flame to the end of the wick 36 it is black, appearing burnt, except for the last 0,5 cm, where it glows red 37 . The wick curls over about 3 mm from its end 38 . As the candle becomes shorter, the wick shortens too, so as to extend roughly a constant length above the top of the candle 39 . Heat is emitted by the flame 40 , enough so that it becomes uncomfortable in 10 to 20 seconds if one holds his finger 10 cm to the side of the quiet flame 41 or 10 – 12 cm above the flame 42 . O’Connor Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 462,

Dual Perceptions

Stack of Blocks

Perception of Motion

www.unit5.org/chemistry Unit 1 Introduction to Chemistry Internet web site: www.unit5.org/christjs

A C o l o r f u l Demonstration: The Remsen Reaction Click to see VIDEO

Vocabulary - Intro. to Chemistry Keys Vocabulary - Introduction to Chemistry Vocabulary - Introduction to Chemistry http://www.unit5.org/chemistry/intro.html

Safety

Basic Safety Rules Use common sense. No unauthorized experiments. No horseplay. Handle chemicals/glassware with respect.

Safety Features of the Lab safety shower fire blanket fire extinguisher eye wash fume hood circuit breaker switch

Government Regulation of Chemicals Chemical Stewardship Consumer Worker Environment FDA, USDA, Consumer Product Safety Commission OSHA EPA The government regulates chemicals to reduce the risk to the…

Government Regulation The government regulates chemicals to protect the… OSHA worker FDA USDA FAA CPSC consumer EPA environment

Thalidomide Prescription drug for morning sickness Drug can be made in two ways Put together same material in more than one way. A = “good” drug (stops morning sickness) B = “bad” drug (birth defects) Side-effect from “bad” drug Stopped development in fetus Short arms; “flipper-babies”

“Happy” & “Sad” Balls Cis-isomer Sad ball Trans-isomer Happy ball

Mercury Poisoning One tiny drop of mercury shatters lives and science LYME, N.H. (AP) — It was just a drop of liquid, That night, Leon drove her to the emergency just a tiny glistening drop. It glided over her glove room. It was Monday, Jan. 20, 1997, five months like a jewel. since she had spilled the drop in the lab. Scientist Karen Wetterhahn knew the risks: The Just a single drop of liquid. Yet somehow it had bad stuff kills if you get too close. penetrated her skin. She took all the precautions working with mer- By the weekend, Karen couldn't walk, her speech cury in her Dartmouth College lab — wearing pro- was slurred and her hands trembled. Leon paced the tective gloves and eye goggles, working under a house. "Virus" seemed an awfully vague diagnosis, ventilated hood that sucks up chemical fumes. for symptoms that were getting worse every day. So on that sunny day in August, when she acci- "It's mercury poisoning," Dr. David Nierenberg dentally spilled a drop, she didn't think anything of said. "We have to start treatment immediately." it. She washed her hands, cleaned her instruments Leon hung up with relief. At last, they understood and went home. the problem. Now maybe they could fix it. It was just a drop of liquid, just a tiny glistening It seemed impossible to believe that anything drop. could be wrong with Karen Wetterhahn, one of At first, friends thought she had caught a stomach those quietly impressive individuals whose lives bug on her trip to Malaysia. It wasn't until she seemed charmed from the start. started bumping into doors that her husband, Leon Serious and hardworking, she excelled at every - Webb, began to worry. Karen, always so focused, thing she turned to — science or sailing or skiing. always so sure of her next step, was suddenly falling She grew up near Lake Champlain in upstate New down as if she were drunk. York in a family so close that when she and her only In 15 years together, she had never been sick, nev- sister became mothers, they named their daughters er stopped working, never complained. Leon was after each other: Charlotte and Karen. stunned when she called for a ride home from work. Karen was always the brilliant one of the family, Over lunch a few days later, Karen confided to her the one who would do great things. And she did, be- best friend, Cathy Johnson, that she hadn't felt right coming the first woman chemistry professor at for some time. Words seemed to be getting stuck in Dartmouth, running a world-renowned laboratory her throat. Her hands tingled. It felt like her whole on chromium research, devoting herself to her body was moving in slow motion. work. "Karen," Johnson said as she drove her back to It was important work, the kind that could lead to the college, "we've got to get you to the hospital." cures for cancer and AIDS. Karen thrived on it. She "After work," Karen promised, walking unsteadi- loved nothing more than experimenting with a ly into the Burke chemistry building for the last chemical, figuring out its bad side and how it breaks time. down living things. Karen Wetterhahn, a chemistry Professor at Dartmouth College, died of mercury poisoning after spilling just one drop in a labor- atory on Aug. 14, 1996. The mercury penetrated her skin through gloves.

Lead Poisoning ( Plumbism) LD 50 = mg / kg Effects: slow mental development, lack of concentration Small children may accidentally ingest lead-based paints that peel off from window sills and walls. Lead accumulates near bone joints – lighter color on X-ray is lead.

Safety Symbols SAFETY CLOTHING This symbol is to remind you to wear a laboratory apron over your street clothes to protect your skin and clothing from spills. SAFETY GOGGLES This symbol is to remind you that safety goggles are to worn at all times when working in the laboratory. For some activities, your teacher may also instruct you to wear protective gloves. GLOVES This symbol is to remind you to wear gloves to protect your hands from contact with corrosive substances, broken glass, or hot objects. HEATING This symbol indicates that you should be careful not to touch hot objects with your bare hands. Use either tongs or heat-proof gloves to pick up hot objects.. FIRE This symbol indicates the presence of an open flame. Loose hair should be tied back or covered, and bulky or loose clothing should be secured in some manner. CORROSIVE SUBSTANCE This symbol indicates a caustic or corrosive substance - most frequently an acid. Avoid contact with skin, eyes, and clothing. Do not inhale vapors. BREAKAGE This symbol indicates an activity in which the likelihood of breakage is greater than usual, such as working with glass tubing, funnels and so forth. DANGEROUS VAPORS This symbol indicates the presence of or production of poisonous or noxious vapors. Use the fume hood when directed to do so. Care should be taken not to inhale vapors directly. When testing an odor, use a wafting motion to direct the vapor toward your nose. EXPLOSION This symbol indicates that the potential for an explosive situation is present. When you see this symbol, read the instructions care- fully and follow them exactly .. POISON This symbol indicates the presence of a poi- sonous substance. Do not let such a substance come in contact with your skin and do not inhale its vapors. ELECTRICAL SHOCK This symbol indicates that the potential for an electrical shock exists. Read all instructions carefully. Disconnect all apparatus when not in use. RADIATION This symbol indicates a radioactive substance. Follow your teacher's instructions as to proper handling of such substances.. DISPOSAL This symbol indicates that a chemical should be disposed of in a special way. Dispose of these chemicals as directed by your teacher. HYGIENE This symbol is to remind you to always wash your hands after completing a labor- atory investigation. Never touch your face or eyes during a laboratory investigation.

Safety Symbols Eye Protection Required Clothing Protection Required Hand Protection Required Chemical Safety Caustic Substance Heat Protection Glassware Safety Laboratory Hygiene Sharp Object Hazard Waste Disposal

Safety Equipment Fire Extinguisher Type A Type B Type C Safety Goggles Safety Shower

Chemical Burns Chemical burns on feet . Skin burned by chemicals Flammable Reactive Health Special

Laboratory Safety Rules DANGER

SAFETY in the Science Classroom Obey the safety contract Use common sense No unauthorized experiments Wear safety glasses Safety is an attitude! Don’t take anything out of lab Read and follow all instructions

Material Safety Data Sheet (MSDS) Gives information about a chemical. Lists “Dos” and “Don’ts.”

Material Safety Data Sheet Keys Material Safety Data Sheet questions Material Safety Data Sheet questions Acetone MSDS http://www.unit5.org/chemistry/intro.html

Chemical Exposure a one-time exposure causes damage acute exposure chronic exposure damage occurs after repeated exposure

How Toxic is “Toxic?” Flammable Explosive Radioactive Corrosive Irritant Toxic Chronic toxicity : low doses repeated over a long period of time Acute toxicity : immediate effect of a substance as a result of a single dose “Lethal Dose 50%” LD 50 Chemicals may cause harm in many different ways.

Toxicity Which is more toxic? http://lansce.lanl.gov/training/FST2004/images04/chemicals1.gif

Toxicity Which is more toxic? Chemical A: LD 50 = 3.2 mg/kg Chemical B: LD 50 = 48 mg/kg Chemical A is more toxic because less of it proves fatal to half of a given population.

the lethal dosage for 50% of animals on which the chemical is tested LD 50 There are various ways an LD 50 can be expressed. For example, acetone has the following LD 50 s: ORL-RAT LD 50 : 5,800 mg/kg IHL-RAT LD 50 : 50,100 mg/m 3 -h SKN-RBT LD 50 : 20 g/kg

Knowledge = Safety Material Safety Data Sheet (MSDS) Lists hazards, special handling instructions, and risks associated with a material. Supplied by manufacturer. Acute Exposure Single episode can cause great damage Chronic Exposure Many episodes over a period of time cause damage Carcinogen – causes cancer Mutagen – causes mutations (genetic defects) Tetragen – causes birth defects Neurotoxin – severely poisonous and toxic

Science

Basic research leads us to a greater understanding of how the natural world operates.

Applied research aims to develop useful applications from the knowledge gained from basic research.

The Functions of Science pure science applied science the search for knowledge; facts using knowledge in a practical way

Science attempts to establish cause-effect relationships. 

Pure Science The search for facts about the natural world. ? In science, we often try to establish a cause-effect relationship. Driven by curiosity : the need to know, explore, conquer something new.

Applied Science The practical application of scientific discoveries. Also known as “ technology ” - Used to improve our lives Cell phones Biodegradable garbage bags

Corning Glass NASA’s Problem Design a material that is clear and can with- stand extreme differences in temperature without fail- ing (cracking). Corning Glass FAILED…but SUCCEEDED at making great cookware that can withstand extremes in temperature. Design a face shield to protect and provide clear vision.

Fertilizers ( 5 - 15 - 10 ) Nitrogen ( N ) Promotes vegetative growth, making the plants lush and green Excess nitrogen: few blooms (flowers) Phosphorous ( P ) Gives energy and vitality Promotes rapid maturity and flowering Potassium ( K ) Promotes strong plant growth and deep roots Helps plants become more disease-resistant Fertilizers help plants produce more food.

saccharin A compound, C 7 H 5 NO 3 S, that is several hundred times sweeter than can sugar and is used as a calorie-free sweetener. Table Sugar = sucrose (glucose + fructose) Formula: C 12 H 22 O 11 [C 12 (H 2 O) 11 ] Dehydration of Sucrose: C 12 H 22 O 11 + 11 H 2 SO 4 12 C + 11 H 2 SO 4 . H 2 O HOCH 2 HOCH 2 HO OH OH OH HO O O O CH 2 OH

risk-benefit analysis weigh pros and cons before deciding Because there are many considerations for each case, “50/50 thinking” rarely applies.

How does scientific knowledge advance? 1. curiosity 2. good observations 3. determination 4. persistence

Aluminum Mining Charles Martin Hall 1850s: aluminum sold for $500 / pound Developed method to extract aluminum from bauxite Hall’s method 1 pound Al costs 30 cents 4-6 pounds bauxite current 1 lb Al + =

The Scientific Method

Guiding Questions Scientific explanations must meet certain criteria: they should be logical, respect the rules of evidence, be open to criticism, report methods and procedures, and make knowledge public. Scientific experiments are conducted after much thought about what may be causing the phenomena in order to isolate important factors. In order to isolate these factors careful planning, including addressing safety issues, must be taken into consideration before attempting experiments. In order to draw a valid conclusion from an experiment, all variables except for that which is being tested must be controlled. Measurements communicate not only a magnitude and the system of measurement (unit) but also information about the tool used to make the measurement through precision (significant figures) and uncertainty

Pseudoscience…definitely NOT the Scientific Method

Checkbook Activity Keys Checkbook Activity- Scientific Method Checkbook Activity- Scientific Method http://www.unit5.org/chemistry/intro.html

Fundamental Properties of Models A model does not equal reality. Models are oversimplifications, and are therefore often wrong. Models become more complicated as they age. We must understand the underlying assumptions in a model so that we don’t misuse it.

Episode 4 - Modeling The Unseen VIDEO ON DEMAND Scientific investigators need to explain things beyond the realm of ordinary perception. The models used by scientists often represent flights of intuition and invention. Focusing on some examples of models used in chemistry, this program emphasizes one classic example that explains the behavior of gases. World of Chemistry The Annenberg Film Series

Scientific Method Scientific Method Scientific Law Scientific Method and Law Theories and Laws Why Dinosaurs Disappeared The Hellenic Market Four-Element Theory Drunken Goldfish Science and Morality

Using the scientific method requires that one be a good observer. observation inference involves a judgment or assumption uses the five senses

The Skeptical Chemist Robert Boyle In “ The Sceptical Chymist” Boyle stated that scientific speculation was worthless unless it was supported by experimental evidence . This principle led to the development of the scientific method . (1661)

observation vs. inference what you sense involves a judgment or measure

“My mother the eye doctor” Observation or Inference? One player is holding a bat. The player holding the bat is talking. One of the teams is called the “Reds.” One player is wearing a catcher’s mask. One player is a catcher. Names are written on the uniforms. The players in the picture are on opposite teams. The adult is the umpire. The piece of paper is a note from the mother of the batter. The adult is holding a piece of paper. The mother of the batter is an optometrist or opthalmologist (an eye doctor).

Data Observations are also called data . There are two types of data. qualitative data quantitative data descriptions; measurements ; no numbers must have numbers and UNITS

Parts of the Scientific Method Identify an unknown. Make a hypothesis (a testable prediction). Experiment to test the hypothesis. Draw a valid conclusion .

Hypotheses A tentative explanation for the observations May not be correct, but it puts the scientist’s understanding of the system being studied into a form that can be tested Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Experiments Tests the validity of the hypothesis Are systematic observations or measurements made under controlled conditions, in which the variable of interest is clearly distinguished from any others If experimental results are reproducible, they are summarized in a law. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

A Scientific Experiment procedure the order of events in an experiment; the “recipe” Experiments must be controlled ; they must have two set-ups that must differ by only one variable. The conclusion must be based on the data. variable any factor that could influence the result

A Controlled Experiment?

Introduction to Qualitative Analysis Keys Introduction to Qualitative Analysis Introduction to Qualitative Analysis http://www.unit5.org/chemistry/intro.html

Scientific Method Observations Hypothesis Experimentation Controlled (one variable changed at a time) Collect data (quantitative and qualitative) Analyze data (graph, statistics…trends) Form valid conclusion. After many experiments…form a theory .

Fundamental Properties of Models A model does not equal reality. Models are oversimplifications, and are therefore often wrong. Models become more complicated as they age. We must understand the underlying assumptions in a model so that we don’t misuse it.

Scientific Law vs. Scientific Theory Law of Gravity A theory tries to explain why or how something happens. A law states what happens. Theory of Gravity Atomic Theory Collision Theory of Reactions

Experiments Law – A verbal or mathematical description of a phenomenon that allows for general predictions – Describes what happens and not why – Unlikely to change greatly over time unless a major experimental error is discovered Theory – Attempts to explain why nature behaves as it does – Is incomplete and imperfect, evolving with time to explain new facts as they are discovered Copyright 2007 Pearson Benjamin Cummings. All rights reserved.

Theory vs. Natural Law Scientific theory Natural law Experiment Hypothesis analyze additional data analyze initial observations

Make observation Ask question Develop hypothesis Test hypothesis with an experiment Analyze data and draw conclusions Hypothesis IS supported Hypothesis is NOT supported Develop theory Test hypothesis with further experiments Revise hypothesis Wysession, Frank, Yancopoulos, Physical Science Concepts in Action , 2004, page 8 Scientific Method

Then And Question Research Hypothesis Procedure/ Method Data Observations Conclusion What does the scientist want to learn more about? Gathering of information An “Educated” guess of an answer to the question Written and carefully followed step-by-step experiment designed to test the hypothesis Information collected during the experiment Written description of what was noticed during the experiment Was the hypothesis correct or incorrect? Next Then Next And Finally First Scientific Method An Overview

Wheel of Scientific Inquiry Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. Broad Questions Learn What Is Known Make Observations Narrow the Focus Specific Questions Document Expectations Perform Experiments Confirm Results Reflect on Findings Communicate With Others

Results confirmed by other scientists – validate theory . Data do not support hypothesis – revise or reject hypothesis Stages In The Scientific Method OBSERVING collecting data measuring experimenting communicating TESTING predicting experimenting communicating collecting data measuring THEORIZING constructing models predicting communicating PUBLISH RESULTS communicating FORMULATING HYPOTHESES organizing and analyzing data classifying inferring predicting communicating

Reviewing Concepts What is Science? How does the scientific process start and end? How are science and technology related? What are the branches of natural science? Explain the advantages and disadvantages of subdividing science into many different areas. Why do scientists seek to discover new laws of the universe?

Reviewing Concepts Using a Scientific Approach What is the goal of scientific methods? How does a scientific law differ from a scientific theory? Why are scientific models useful? What are three types of variables in a controlled experiment? Does every scientific method begin with an observation? Explain.

Scientific Law Laws of nature never change. Experiments Observations Charles’s Law V 1 V 2 T 1 T 2 = Scientific Law

Theories and Laws The Earth is flat… Speeding kills (Audubon, Germany); No explanation of why…but the theory is if you drive at 120 mph and crash, an ambulance won’t need to be called (only next of kin). seat belts save lives… LAW : 65 mph and wear seat belt

Galileo Galilei (1564–1642) Among other things, rolled spheres down inclined planes. h h h Galileo nearly formulated concept of inertia.

Why Dinosaurs Disappeared Dinosaurs Meteor Earth Dust Cloud Moon is formed Ice Age - Glaciers RIP Meteor Crater Sun blocked Evidence… A theory…

The Original Metric Reference H 2 O H 2 O = 1 meter = 1 kilogram = 1 liter Length Mass Volume 1 kg 1/10 m 1/10 m 1/10 m 1/10,000,000

The Hellenic Market Fire Water Earth Air ~ ~

Four Element Theory Plato was an atomist Thought all matter was composed of 4 elements: Earth Water Fire Air Ether (close to heaven) ‘MATTER’ FIRE EARTH AIR WATER Hot Wet Cold Dry Relation of the four elements and the four qualities Graphic courtesy of Ken Costello @ www.chemistryland.com

Anaxagoras (Greek, born 500 B.C.) Suggested every substance had its own kind of “ seeds ” that clustered together to make the substance, much as our atoms cluster to make molecules. Some Early Ideas on Matter O’Connor Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 26, Empedocles (Greek, born in Sicily, 490 B.C.) Suggested there were only four basic seeds – earth, air, fire, and water . The elementary substances (atoms to us) combined in various ways to make everything. Democritus (Thracian, born 470 B.C.) Actually proposed the word atom (indivisible) because he believed that all matter consisted of such tiny units with voids between, an idea quite similar to our own beliefs. It was rejected by Aristotle and thus lost for 2000 years. Aristotle (Greek, born 384 B.C.) Added the idea of “qualities” – heat, cold, dryness, moisture – as basic elements which combined as shown in the diagram (previous page). Hot + dry made fire; hot + wet made air, and so on.

Drunken Goldfish Fighting fish Uneducated worms appear to acquire knowledge by eating educated worms. Rats are more attracted to other rats than to tennis balls. Disco music Conclusions must be supported by data to be valid. “Goldfish immersed in 3.1% alcohol will overturn within 6 to 8 minutes. Because of this tendency to fall over when drunk, the goldfish is a good model for research on the effects of alcohol. When preliminary studies indicated that goldfish tended to forget things when drunk, and that Siamese Fighting Fish became more aggressive after a little drink or two, their attraction as experimental animals became irresistible.” Hartston, Drunken Goldfish & Other Irrelevant Scientific Research , page 53

Evidence must be reproducible

Theory A single comprehensive idea that has stood up to repeated scrutiny

The Scientific Attitude

“This attitude is one of inquiry, experimentation, honesty, and a faith that all natural phenomena can be explained.”

Science and Morality Science must operate in the realms or morality that society believes in Joseph Mengele Atomic Bomb Cloning of humans Stem cell research

Scientific Method and Law

Combustion & Phlogiston Phlogiston Theory Combustion Theory Burning Magnesium Metal in an Open Container Burning Magnesium Metal in a Closed Container Lighting a Bunsen Burner Flame Temperature Distribution

Phlogiston Theory (a) When an object burns it gives off a substance called phlogiston . (b) When the space surrounding the burning object is filled with phlogiston, the object will no longer be able to burn. Phlogiston theory of burning Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3 rd Edition, 1990, page 4 phlogiston phlogiston (a) (b)

Combustion Theory Modern theory of burning (c) When an object burns, it uses up a substance ( oxygen ) in the surrounding space. When the space surrounding the burning object has too little oxygen in it, the object will no longer be able to burn. Antoine Lavoiser Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3 rd Edition, 1990, page 4 oxygen (c) (d)

Phlogiston Theory of Burning 1. Flammable materials contain phlogiston. 2. During burning, phlogiston is released into the air. 3. Burning stops when… …object is out of phlogiston, or …the surrounding air contains too much phlogiston.

Burning Magnesium Metal in an Open Container Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3 rd Edition, 1990, page 77 strip of magnesium metal Before burning After burning white powder strip of magnesium metal white powder

Burning Magnesium Metal in an Open Container Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3 rd Edition, 1990, page 77 strip of magnesium metal Before burning After burning white powder strip of magnesium metal white powder mass increased Mg didn’t LOSE phlogiston… but gained oxygen!

Burning Magnesium Metal in a Closed Container Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3 rd Edition, 1990, page 77 strip of magnesium metal Before burning After burning white powder nichrome wire connected to a battery 2 Mg + O 2  2 MgO mass conserved

The Bunsen Burner Mi xt r e of GAS and AIR Barrel Air Gas Collar Hottest part Oxidizing flame Spud

The Bunsen Burner Oxidizing flame Mi xt r e of GAS and AIR Barrel Air Gas Collar Spud Hottest part Robert Bunsen

Lighting a Bunsen Burner Always light match BEFORE turning on gas. inner, less transparent, brighter, greenish-blue cone outer, transparent, dim blue cone gas valve air adjustment gas adjustment

Flame Temperature Distribution Bunsen / Tirrill Burner Flame The Bunsen / Tirrill burner and Meker burner differ not only in the higher maximum temperature produced, but also in heat distribution within the flame. 1540 o C 1550 o C 1560 o C 1540 o C 1470 o C 1560 o C 520 o C 1450 o C 350 o C 300 o C Meker Burner Flame 1640 o C 1660 o C 1660 o C 1660 o C 1670 o C 1720 o C 1720 o C 1670 o C 1680 o C 1720 o C 1775 o C

Laboratory Equipment

Chemistry

How did Chemistry Become a Science? http://en.wikipedia.org/wiki/History_of_chemistry

Alchemy vs. Chemistry The Alchemist The Alchemist’s Dream Zinc Pennies Alchemy vs. Chemistry Pure Science Applied Science Aluminum Mining Corning Glass Fertilizers (5-15-10) Areas of Chemistry Stereotypes of Chemists A Career in Chemistry Forensic Scientist The Scope of Chemistry Starting Salaries

The Alchemist Frankly, I’d be satisfied if I could turn gold into lead!

The Alchemist’s Dream COPPER “ SILVER ” “ GOLD ” Zinc coated Brass = Copper + Zinc Penny into Gold - Alchemist Dream

Copper was used to make bullet shells in WW II. By 1943, the supply of copper metal was in short supply. The US government did not want to ‘waste’ copper on making pennies. Pennies were made with steel metal. They looked silver. Zinc Pennies Before 1982, all pennies were solid copper (except 1943). After 1982, pennies were made from zinc. A thin coating of copper was pressed on the zinc. A shortage of copper drove the price of copper up in the early 1980s. If melted down, the copper could be sold for more than one cent.

Democrat vs. Republican Alike Different Different Topic Topic Democrat politicians ethical un conservative liberal right left support big business support 'little man' ? Republican

Alchemy vs. Chemistry Alike Different Chemistry Different Topic Topic Alchemy

“I think you’ve crossed that thin line between transmuting and cooking.”

Paracelsus Man consisted of three elements SALT represented the body SULFUR the soul MERCURY the spirit He thought he could rearrange the amounts of the elements to change man. He desired immortality and searched for a mystical elixir of life.

The Beginnings The Greeks believed there were four elements. early practical chemistry: household goods, weapons, soap, wine, basic medicine earth air fire water D ~ ~ D ___ D ___

Timeline 2000 1000 300 AD American Independence (1776) Issac Newton (1642 - 1727) 400 BC Greeks (Democratus ~450 BC) Discontinuous theory of matter ALCHEMY Greeks (Aristotle ~350 BC)) Continuous theory of matter

Alchemy Allegedly, this substance would turn cheap metals into gold. In Europe, alchemy was the quest for the Philosopher’s Stone (the elixir, the Sorcerer’s Stone).

transmutation In ordinary chemical reactions, we cannot transmute elements into different elements. changing one substance into another COPPER GOLD   Philosopher’s Stone

Early Ideas on Elements Robert Boyle stated... A substance was an element unless it could be broken down to two or more simpler substances. Air therefore could not be an element because it could be broken down in to many pure substances. Robert Boyle

Alchemy After that 'chemistry' was ruled by alchemy. They believed that that could take any cheap metals and turn them into gold. Alchemists were almost like magicians. elixirs, physical immortality

Alchemy Symbols Alchemy Symbols

Alchemy . . . . . . . . . . . . . . . GOLD SILVER COPPER IRON SAND Alchemical symbols for substances… transmutation : changing one substance into another In ordinary chemistry, we cannot transmute elements. D

GOLD SILVER COPPER IRON . . . . . . . . . . . . . . . SAND Alchemy (~500 – 1300 A.D.) Alchemical symbols for substances… transmutation : changing one substance into another the quest for the Philosopher’s Stone It was supposed to change cheap metals into gold. In ordinary chemistry, we cannot transmute elements. Contributions of alchemists: lab apparatus / procedures how to make some alloys properties of some elements The Alchemist, by David Teniers

Alchemy was practiced in many regions of the world, including China and the Middle East. Alchemy arrived in western Europe around the year 500 C.E. Modern chemistry evolved from alchemy.

Contributions of alchemists: Information about elements - the elements mercury, sulfur, and antimony were discovered - properties of some elements Develop lab apparatus / procedures / experimental techniques - alchemists learned how to prepare acids. - developed several alloys - new glassware

What is Chemistry? the study of matter and its changes

C H E M Y S T E R Y C H E M - I S - T R Y C H E M A S T E R Y C H E M I S E R Y C h e m i s t r y

Areas of Chemistry Organic Inorganic Analytical Physical Biochemistry The study of most carbon -containing compounds The study of all substances not classified as organic, mainly those compounds that do not contain carbon The identification of the components and composition of materials The study of the properties, changes, and relationships between energy and matter The study of substances and processes occurring in living things

Areas of Chemistry organic physical inorganic biochemistry everything except carbon e.g., compounds containing metals the study of carbon- containing compounds measuring physical properties of substances e.g., the melting point of gold the chemistry of living things

Stereotypes of Chemists Male Middle-aged White Lab coat Nerd / Geek

Careers in Chemistry research (new products) production (quality control) development (manufacturing) chemical sales software engineering teaching

Careers in Chemistry research (new products) production (quality control) development (scale up manufacturing processes) chemical sales software engineering teaching The skills you will develop by an earnest study of chemistry will help you in any career field. Pharmacist

Areas of Chemistry organic : the study of carbon-containing compounds inorganic : studies everything except carbon (e.g., metals) biochemistry : the chemistry of living things physical : measuring physical properties of substances chemistry : the study of matter and its changes

Biological Compounds Biological Compounds Proteins Carbohydrates Lipids Nucleic Acids a polymer composed of amino acids a simple sugar or a polymer composed of simple sugars a fat, an oil, a wax, or a steroid a polymer composed of a sugar, an organic base, and phosphoric acid Corwin, Introductory Chemistry , 2005, page 551 Biochemical compounds can be classified as one of the following: protein, carbohydrate, lipid, or nucleic acid.

EPA environment consumer worker OSHA Consumer Product Safety Commission, USDA, BATF, FDA Government Regulation of Chemicals …to protect the…

A Career in the Field of Chemistry Research Chemist Chemist who works in Development

Production Chemists and Technicians Other Jobs for Chemists Chemical sales, software engineering, patent law, teaching

The skills you will develop by an earnest study of chemistry will help you in any career field.

The Scope of Chemistry All fields of endeavor are affected by chemistry. -- petroleum products -- synthetic fibers -- pharmaceuticals -- bulk chemical manufacturing #1 chemical = sulfuric acid (H 2 SO 4 ) gasoline, oil, diesel fuel, heating oil, asphalt nylon, polyester, rayon, spandex medicines, cancer drugs, VIAGRA 1 in 10,000 new products gets FDA approval

The Scope of Chemistry bulk chemical manufacturing petroleum products pharmaceuticals synthetic fibers acids, bases, fertilizers fuels, oils, greases, asphalt 1 in 10,000 new products gets FDA approval nylon, polyester, rayon, spandex

Research Basic Research Carried out for the sake of increasing knowledge Driven by curiosity or a desire to know Roy Plunkett ‘discovers’ Teflon is a nonstick material Applied Research Carried out to solve a specific problem Safer refrigerant that does not harm ozone layer Technological Development Production and use of products that improve our quality of life Computer chips, biodegradable materials, catalytic converters for automobiles

Forensic Scientist Arson is suspected in the burning of this house. Gasoline, paint, and bottled gas are extremely volatile. Use science to solve crimes Arson investigation DNA fingerprinting Luminol test for blood

The Scope of Chemistry The chemical industry has a large effect on our lives. bulk chemical manufacturing synthetic fibers petroleum products pharmaceuticals ALL fields of endeavor are affected by chemistry.

Starting Yearly Salaries Chemist BS $45,400 MS $53,500 PhD $66,000 Related Occupations : Chemical Engineering, biological scientist, chemical technologist, physicists, medical scientists vs. Communications BS MS PhD Physician Resident $30,753 - $41,895 Earning $120,000 - $240,000 1998 Average Salaries

All fields of endeavor are affected by chemistry .

World of Chemistry The Annenberg Film Series Episode 1 - The World of Chemistry VIDEO ON DEMAND The relationships of chemistry to the other sciences and to everyday life are presented. The world of chemistry is introduced by providing highlights of key sequences and themes from programs in the series. The relationships of chemistry to the other sciences and to everyday life are presented. Running Time: 28:38

Chemistry and Manipulating Numerical Data

Measurements Numbers science is based on measurements all measurements have: - magnitude - uncertainty - units mathematics is based on numbers exact numbers are obtained by: - counting - definition

Graphs

Bar Graph shows how many of something are in each category

Unit 1 Test – Honor’s Chemistry Introduction to Chemistry 50 45 40 35 30 2 nd Hour 5 th Hour 6 th Hour 8 th Hour 1 st Hour 27 A’s 55 B’s 35 C’s 5 D’s This is also about what the quarter grades will look like. September 14, 2007 Avg: 40.9 + 4.0 83.8 + 8.0 %

Pie Graph shows how a whole is broken into parts Percentage of Weekly Income

Line Graph shows continuous change Stock Price over Time

Elements of a “good” line graph axes labeled, with units use the available space title neat

How to read a graph Interpolate - read between data points What volume would the gas occupy at a temperature of 150 K? Extrapolate - read data beyond data points What volume would the gas occupy at a temperature of 260 K? Which do you have more confidence in? Why? (independent variable) (dependent variable) 7 L ~4 L

Graphs Line Graph Used to show trends or continuous change Bar Graph Used to display information collected by counting Pie Graph Used to show how some fixed quantity is broken down into parts

Line Graph Mass (g) Age (Year of Penny) Mass (g) Age (Year of Penny) Mass (g) Age (Year of Penny) Mass (g) Age (Year of Penny) How does the mass of a penny change with age? A B C D

Bar Graph Number of Students Chemistry Grades Descriptive title Legend Axis labeled (with units)

Pie Graph

Pie Graphs

Graphing Keys Graphing Graphing http://www.unit5.org/chemistry/intro.html

Reviewing Concepts Presenting Scientific Data How do scientists organize data? How can scientists communicate experimental results? What does a given point represent on a line graph? The density of copper is 8.92 g/cm 3 . If you plotted the volume in cubic centimeters, what would the slope of the line be?

Conversion Factors and Unit Cancellation

A physical quantity must include: Number + Unit

Calculation Corner: Unit Conversion 1 foot = 12 inches

Calculation Corner: Unit Conversion 1 foot = 12 inches 1 foot 12 inches = 1

Calculation Corner: Unit Conversion 1 foot = 12 inches 1 foot 12 inches = 1 12 inches 1 foot = 1

Calculation Corner: Unit Conversion 1 foot 12 inches 12 inches 1 foot “Conversion factors”

Calculation Corner: Unit Conversion 1 foot 12 inches 12 inches 1 foot “Conversion factors” 3 feet 12 inches 1 foot = 36 inches ( ) ( )

How many cm are in 1.32 meters? applicable conversion factors: equality: or X cm = 1.32 m = 1 m = 100 cm ______ 1 m 100 cm We use the idea of unit cancellation to decide upon which one of the two conversion factors we choose. ______ 1 m 100 cm ( ) ______ 1 m 100 cm 132 cm (or 0.01 m = 1 cm)

How many meters is 8.72 cm? applicable conversion factors: equality: or X m = 8.72 cm = 1 m = 100 cm ______ 1 m 100 cm Again, the units must cancel. ______ 1 m 100 cm ( ) ______ 0.0872 m 1 m 100 cm

How many feet is 39.37 inches? applicable conversion factors: equality: or X ft = 39.37 in = 1 ft = 12 in ______ 1 ft 12 in Again, the units must cancel. ( ) ____ 3.28 ft 1 ft 12 in ______ 1 ft 12 in

How many kilometers is 15,000 decimeters? X km = 15,000 dm = 1.5 km ( ) ____ 1,000 m 1 km 10 dm 1 m ( ) ______

How many seconds is 4.38 days? = 1 h 60 min 24 h 1 d 1 min 60 s ____ ( ) ( ) ____ ( ) _____ X s = 4.38 d 378,432 s 3.78 x 10 5 s If we are accounting for significant figures, we would change this to…

Real Life Chemistry Keys Real Life Chemistry Real Life Chemistry http://www.unit5.org/chemistry/intro.html

Simple Math with Conversion Factors

Measured dimensions of a rectangle: Find area of rectangle. A = L . W = (9.70 cm)(4.25 cm) length (L) = 9.70 cm width (W) = 4.25 cm L W = Example Problem 41.2 cm 2 . cm

Convert 41.2 cm 2 to m 2 . 100 cm 1 m ( ) ______ X m 2 = 41.2 cm 2 X m 2 = 41.2 cm . cm Recall that… 41.2 cm 2 = 41.2 cm . cm 100 cm 1 m ( ) ______ X m 2 = 41.2 cm 2 = 0.412 m 2 = 0.412 cm . m WRONG! ( ) ______ 100 cm 1 m = 0.00412 m 2 ( ) ______ 100 cm 1 m 2 = 0.00412 m 2

Convert 41.2 cm 2 to mm 2 . X mm 2 = 41.2 cm 2 X mm 2 = 41.2 cm . cm Recall that… 41.2 cm 2 = 41.2 cm . cm 1 cm 10 mm ( ) _____ = 4,120 mm 2 = 1 cm 10 mm ( ) _____ 4,120 mm 2 1 cm 10 mm 2 ( ) _____

Measured dimensions of a rectangular solid: Find volume of solid. L W H Length = 15.2 cm Width = 3.7 cm Height = 8.6 cm V = L . W . H = (15.2 cm)(3.7 cm)(8.6 cm) = 480 cm 3

Convert to m 3 . X m 3 = 480 cm 3 = 0.000480 m 3 100 cm 1 m 3 ( ) _____ X m 3 = 480 cm 3 = X m 3 = 480 100 cm 1 m ( ) _____ 100 cm 1 m ( ) _____ 100 cm 1 m ( ) _____ = or cm . cm . cm 1 m 1000000 cm ( ) _________ 3 3 4.80 x 10 -4 m 3 or 3 2 cm

Measured dimensions of a rectangular solid: Find volume of solid. L W H Length = 15.2 cm Width = 3.7 cm Height = 8.6 cm V = L . W . H = (0.152 m)(0.037 m)(0.086 m) = 0.000480 m 3 0.152 m 0.037 m 0.086 m Convert to m 3 ...

Convert to mm 3 .

By what factor do mm and cm differ? 10 By what factor do mm 2 and cm 2 differ? 100 By what factor do mm 3 and cm 3 differ? 1,000 1 cm = 10 mm (1 cm) 2 = (10 mm) 2 1 cm 2 = 100 mm 2 (1 cm) 3 = (10 mm) 3 1 cm 3 = 1000 mm 3

Conversion Factors Keys Conversion Factors Conversion Factors http://www.unit5.org/chemistry/intro.html

Scientific Notation Often used to express very large or very small numbers. Also used to maintain correct number of significant figures.

Form: (# from 1 to 9.999) x 10 exponent 800 = 8 x 10 x 10 = 8 x 10 2 2531 = 2.531 x 10 x 10 x 10 = 2.531 x 10 3 0.0014 = 1.4 / 10 / 10 / 10 = 1.4 x 10 -3

Change to standard form. 1.87 x 10 –5 = 3.7 x 10 8 = 7.88 x 10 1 = 2.164 x 10 –2 = 370,000,000 0.0000187 78.8 0.02164 000000187000000 . .

Change to scientific notation. 12,340 = 0.369 = 0.008 = 1,000,000,000 = 1.234 x 10 4 3.69 x 10 –1 8 x 10 –3 1 x 10 9

Using the Exponent Key on a Calculator EXP EE

EE or EXP means “times 10 to the…” How to type out 6.02 x 10 23 : 6 EE . 3 2 2 6 y x . 3 2 2 x 1 6 . 2 EE 3 2 y x 3 2 x 1 6 . 2 Don’t do it like this… …or like this… …or like this: How to type out 6.02 x 10 23 : 6 EE . 3 2 2 WRONG! WRONG! TOO MUCH WORK.

Also, know when to hit your (–) sign… …before the number, …after the number, …or either one.

Example: 1.2 x 10 5 2.8 x 10 13 But instead is written… = 1 . 2 EE 5 3 2 . 8 EE 1 Type this calculation in like this: This is NOT written… 4.3 –9 4.2857143 –09 Calculator gives… 4.2857143 E–09 or… 4.3 x 10 –9 4.3 E –9 or

= -6.525 x 10 -9 = 5.3505 x 10 3 or 5350.5 = 5.84178499 x 10 -13 report -6.5 x 10 -9 (2 sig. figs.) report 5.35 x 10 3 (3 sig. figs.) report 5.84 x 10 -13 (3 sig. figs.) = 2.904 x 10 23 report 2.9 x 10 23 (2 sig. figs.) = -3.07122 x 10 16 report -3.1 x 10 16 (2 sig. figs.)

Scientific Notation Scientific Notation Converting Numbers to Scientific Notation How to Use a Scientific Calculator

Scientific Notation We often use very small and very large numbers in chemistry. Scientific notation is a method to express these numbers in a manageable fashion. Thus 0.000 000 1 cm can be written 1 x 10 -7 cm . Lets see why… Scientific notation expresses a number as the product of two factors, the first falling between 1 and 10 and the second being a power of 10.

Method to express really big or small numbers. Format is Mantissa x Base Power We just move the decimal point around. Decimal part of original number Decimal you moved 6.02 x 10 23 602000000000000000000000

Scientific Notation 5000 = 5 x 10 3 or 5 3 5 x ( 10 x 10 x 10 ) 5 x 1000 5000 Numbers > one have a positive exponent . Numbers < one have a negative exponent . EE Numbers are written in the form M x 10 n , where the factor M is a number greater than or equal to 1 but less than 10 and n is a whole number . x 10 n

Converting Numbers to Scientific Notation 0 . 0 0 0 0 2 2 0 5 1 2 3 4 5 2.205 x 10 -5 In scientific notation, a number is separated into two parts. The first part is a number between 1 and 10. The second part is a power of ten.

How to Use a Scientific Calculator How to enter this on a calculator: 5.44 7 8.1 4 EE EE 5.44 7 8.1 4 EXP = EXP . 671.6049383 rounded to 6.7 x 10 2 ENTER Davis, Metcalfe, Williams, Castka, Modern Chemistry , 1999, page 52 . Divide: (5.44 x 10 7 ) (8.1 x 10 4 ) . . OR 5.44 00 07 54400000. 8.1 00 04 671.604938 . .

Rule for Multiplication Calculating with Numbers Written in Scientific Notation When multiplying numbers in scientific notation, multiply the first factors and add the exponents . Sample Problem: Multiply 3.2 x 10 -7 by 2.1 x 10 5 ( 3.2 ) x ( 2.1 ) = 6.72 ( -7 ) + ( 5 ) = -2 or 10 -2 6.72 x 10 -2 Exercise: Multiply 14.6 x 10 7 by 1.5 x 10 4 2.19 x 10 12

Rule for Division Calculating with Numbers Written in Scientific Notation When dividing numbers in scientific notation, divide the first factor in the numerator by the first factor in the denominator. Then subtract the exponent in the denominator from the exponent in the numerator. Sample Problem: Divide 6.4 x 10 6 by 1.7 x 10 2 ( 6.4 ) ( 1.7 ) = 3.76 ( 6 ) - ( 2 ) = 4 or 10 4 3.76 x 10 4 Exercise: Divide 2.4 x 10 -7 by 3.1 x 10 14 7.74 x 10 -22 . .

Rule for Addition and Subtraction Calculating with Numbers Written in Scientific Notation In order to add or subtract numbers written in scientific notation , you must express them with the same power of 10. Sample Problem: Add 5.8 x 10 3 and 2.16 x 10 4 ( 5.8 x 10 3 ) + ( 21.6 x 10 3 ) = 27.4 x 10 3 Exercise: Add 8.32 x 10 -7 and 1.2 x 10 -5 1.28 x 10 -5 2.74 x 10 4

Using Scientific Notation for Expressing the Correct Number of Significant Figures Measurement Number of significant figures it contains Measurement Number of significant figures it contains 25 g 0.030 kg 1.240560 x 10 6 mg 6 x 10 4 sec 246.31 g 20.06 cm 1.050 m 0.12 kg 1240560. cm 6000000 kg 6.00 x 10 6 kg 409 cm 29.200 cm 0.02500 g 2 2 7 1 5 4 4 2 7 1 3 3 5 4

Scientific Notation Keys Scientific Notation Scientific Notation http://www.unit5.org/chemistry/intro.html

Basic Concepts in Chemistry

chemical any substance that takes part in, or occurs as a result of, a chemical reaction All matter can be considered to be chemicals or mixtures of chemicals.

chemical reaction a rearrangement of atoms such that “what you end up with” products differs from “what you started with” reactants

methane + oxygen  + H 2 O( g ) carbon dioxide O 2 ( g ) CO 2 ( g ) CH 4 ( g ) +  water + 2 2  Combustion of a Hydrocarbon

NaOH( aq ) water Na( s ) H 2 O( l ) H 2 ( g ) 2 sodium 2 2 hydrogen sodium hydroxide +  + +  + 

Law of Conservation of Mass total mass = total mass of reactants of products R mass = P mass

Black Snake Demonstration The Law of Conservation of Mass “total mass of reactants = total mass of products” During chemical reactions, no measurable change in total mass occurs. Dehydration of sugar with the addition of sulfuric acid. Sugar H 2 SO 4 Click for Video

Basic Concepts in Chemistry sodium + water  hydrogen + sodium hydroxide 2 Na ( s ) + 2 H 2 O ( l )  H 2 ( g ) + 2 Na O H ( s ) Let’s visualize what’s happening at the “particle level”… What happens to the particles during a chemical reaction? They are NOT created or destroyed; they are merely rearranged Is there a change in energy associated with a chemical change? Yes: heat, light, sound - perhaps not easily noticed

2 Na ( s ) + 2 H 2 O ( l )  H 2 ( g ) + 2 Na O H ( s ) Basic Concepts in Chemistry sodium + water  hydrogen + sodium hydroxide Let’s visualize what’s happening at the “particle level”… What happens to the particles during a chemical reaction? They are NOT created or destroyed; they are merely rearranged Is there a change in energy associated with a chemical change? Yes: heat, light, sound - perhaps not easily noticed

Synthesis taking small molecules and putting them together, usually in many steps, to make something more complex Photosynthesis Sunlight Carbon Dioxide Water Oxygen Glucose CO 2 + H 2 O O 2 + C 6 H 12 O 6

Episode 3 - Measurement The Foundation of Chemistry World of Chemistry The Annenberg Film Series VIDEO ON DEMAND Accuracy and precision are fundamental properties to modern chemistry. The distinction between the two terms and their importance in establishing measurement standards in commerce and science are explained. (Running Time: 28:38)

The Metric System from Industry Week, 1981 November 30

No Cussing! The following 4-Letter words are forbidden here: Inch Mile Foot Pint Yard Acre And we never swear the BIG F (use o C) Please keep it clean and Metric

SI System The International System of Units Derived Units Commonly Used in Chemistry Area and Volume: Derived Units Prefixes in the SI System Map of the world where red represents countries which do not use the metric system

A Common System for Trade In 1790, the French government appointed a committee of scientists to develop a universal measuring system. English system of measurement originated in 1215 with the signing of the Magna Carta. It attempted to bring uniform measurements to world trade. It took ~10 years, and they unveiled the Metric system. length meter m mass gram g volume liter L time second s

The International System of Units Length meter m Mass kilogram kg Time second s Amount of substance mole mol Thermodynamic temperature Kelvin K Electric current amperes amps Luminous intensity candela cd Quantity Name Symbol Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3 rd Edition, 1990, page 16

The Original Metric Reference H 2 O = 1 liter Volume 1 kg H 2 O = 1 kilogram Mass 1/10 m 1/10 m 1/10 m = 1 meter Length 1/10,000,000 Earth

The Official Standard Meter

The Official Standard Kilogram

Derived Units Commonly Used in Chemistry Area square meter m 2 Volume cubic meter m 3 Force newton N Pressure pascal Pa Energy joule J Power watt W Voltage volt V Frequency hertz Hz Electric charge coulomb C Quantity Name Symbol

Area and Volume: Derived Units Area = length x width = 5.0 m x 3.0 m = 15 ( m x m ) = 15 m 2 Volume = length x width x height = 5.0 m x 3.0 m x 4.0 m = 60 ( m x m x m ) = 60 m 3

Prefixes in the SI System Power of 10 for Prefix Symbol Meaning Scientific Notation _______________________________________________________________________ mega- M 1,000,000 10 6 kilo- k 1,000 10 3 deci- d 0.1 10 -1 centi- c 0.01 10 -2 milli- m 0.001 10 -3 micro- m 0.000001 10 -6 nano- n 0.000000001 10 -9 The Commonly Used Prefixes in the SI System Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118

Measurement 100 mL Graduated Cylinder Units of Measuring Volume Reading a Meniscus Units for Measuring Mass Quantities of Mass SI-English Conversion Factors Accuracy vs. Precision Accuracy Precision Resolution SI units for Measuring Length Comparison of English and SI Units Reporting Measurements Measuring a Pin Practice Measuring

100 mL Graduated Cylinder Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 119

Instruments for Measuring Volume Graduated cylinder Syringe Volumetric flask Buret Pipet

Units of Measuring Volume 1 L = 1000 mL 1 qt = 946 mL Timberlake, Chemistry 7 th Edition, page 3

Reading a Meniscus 10 8 6 line of sight too high reading too low reading too high line of sight too low proper line of sight reading correct graduated cylinder 10 mL

Units for Measuring Mass 1 kg = 2.20 lb Timberlake, Chemistry 7 th Edition, page 3

Christopherson Scales Made in Normal, Illinois USA Units for Measuring Mass 1 kg = 2.20 lb 1 kg (1000 g) 1 lb 1 lb 0.20 lb

Quantities of Mass Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 25 Earth’s atmosphere to 2500 km Ocean liner Indian elephant Average human 1.0 liter of water Grain of table salt Typical protein Uranium atom Water molecule 10 24 g 10 21 g 10 18 g 10 15 g 10 12 g 10 9 g 10 6 g 10 3 g 10 g 10 -3 g 10 -6 g 10 -9 g 10 -12 g 10 -15 g 10 -18 g 10 -21 g 10 -24 g Giga- Mega- Kilo- base milli- micro- nano- pico- femto- atomo-

Factor Name Symbol Factor Name Symbol 10 -1 decimeter dm 10 1 decameter dam 10 -2 centimeter cm 10 2 hectometer hm 10 -3 millimeter mm 10 3 kilometer km 10 -6 micrometer m m 10 6 megameter Mm 10 -9 nanometer nm 10 9 gigameter Gm 10 -12 picometer pm 10 12 terameter Tm 10 -15 femtometer fm 10 15 petameter Pm 10 -18 attometer am 10 18 exameter Em 10 -21 zeptometer zm 10 21 zettameter Zm 10 -24 yoctometer ym 10 24 yottameter Ym

Scientific Notation: Powers of Ten Rules for writing numbers in scientific notation: Write all significant figures but only the significant figures. Place the decimal point after the first digit, making the number have a value between 1 and 10. Use the correct power of ten to place the decimal point properly, as indicated below. a) Positive exponents push the decimal point to the right. The number becomes larger. It is multiplied by the power of 10. b) Negative exponents push the decimal point to the left. The number becomes smaller. It is divided by the power of 10. c) 10 o = 1 Examples: 3400 = 3.20 x 103 0.0120 = 1.20 x 10-2 Nice visual display of Powers of Ten ( a view from outer space to the inside of an atom ) viewed by powers of 10!

Multiples of bytes as defined by IEC 60027-2 SI prefix Binary prefixes Name Symbol Multiple Name Symbol Multiple kilobyte kB 10 3 (or 2 10 ) kibibyte KiB 2 10 megabyte MB 10 6 (or 2 20 ) mebibyte MiB 2 20 gigabyte GB 10 9 (or 2 30 ) gibibyte GiB 2 30 terabyte TB 10 12 (or 2 40 ) tebibyte TiB 2 40 petabyte PB 10 15 (or 2 50 ) pebibyte PiB 2 50 exabyte EB 10 18 (or 2 60 ) exbibyte EiB 2 60 zettabyte ZB 10 21 (or 2 70 ) yottabyte YB 10 24 (or 2 80 ) A yottabyte (derived from the SI prefix )

Metric Article Keys Metric Article ( questions ) Metric Article (questions) http://www.unit5.org/chemistry/intro.html

SI-US Conversion Factors Relationship Conversion Factors Length Volume Mass 2.54 cm = 1 in. 1 m = 39.4 in. 946 mL = 1 qt 1 L = 1.06 qt 454 g = 1 lb 1 kg = 2.20 lb 1 in 2.54 cm 39.4 in 1 m 1 m 39.4 in. 946 mL 1 qt 1 qt 946 mL 1.06 qt 1 L 1 L 1.06 qt 454 g 1 lb 1 lb 454 g 2.20 lb 1 kg 1 kg 2.20 lb 2.54 cm 1 in and and and and and and

Accuracy vs. Precision Random errors: reduce precision Good accuracy Good precision Poor accuracy Good precision Poor accuracy Poor precision Systematic errors: reduce accuracy (person) (instrument)

Accuracy vs. Precision Random errors: reduce precision Good accuracy Good precision Poor accuracy Good precision Poor accuracy Poor precision Systematic errors: reduce accuracy

Precision Accuracy reproducibility check by repeating measurements poor precision results from poor technique correctness check by using a different method poor accuracy results from procedural or equipment flaws.

Types of errors Systematic Instrument not ‘zeroed’ properly Reagents made at wrong concentration Random Temperature in room varies ‘wildly’ Person running test is not properly trained

Errors Systematic Errors in a single direction (high or low) Can be corrected by proper calibration or running controls and blanks. Random Errors in any direction. Can’t be corrected. Can only be accounted for by using statistics.

Accuracy Precision Resolution subsequent samples time offset [arbitrary units] not accurate, not precise accurate, not precise not accurate, precise accurate and precise accurate, low resolution -2 -3 -1 1 2 3

Standard Deviation The standard deviation, SD, is a precision estimate based on the area score: where x i is the i - th measurement x is the average measurement N is the number of measurements. y x One standard deviation away from the mean in either direction on the horizontal axis (the red area on the graph) accounts for around 68 percent of the people in this group. Two standard deviations away from the mean (the red and green areas) account for roughly 95 percent of the people. Three standard deviations (the red, green and blue areas) account for about 99 percent of the people.

SI Prefixes kilo- 1000 deci- 1 / 10 centi- 1 / 100 milli- 1 / 1000 Also know… 1 mL = 1 cm 3 and 1 L = 1 dm 3

SI System for Measuring Length Unit Symbol Meter Equivalent _______________________________________________________________________ kilometer km 1,000 m or 10 3 m meter m 1 m or 10 m decimeter dm 0.1 m or 10 -1 m centimeter cm 0.01 m or 10 -2 m millimeter mm 0.001 m or 10 -3 m micrometer m m 0.000001 m or 10 -6 m nanometer nm 0.000000001 m or 10 -9 m The SI Units for Measuring Length Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 118

Comparison of English and SI Units 1 inch 2.54 cm 1 inch = 2.54 cm Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 119

Reporting Measurements Using significant figures Report what is known with certainty Add ONE digit of uncertainty (estimation) Davis, Metcalfe, Williams, Castka, Modern Chemistry , 1999, page 46

Measuring a Pin Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 122

Practice Measuring 4.5 cm 4.54 cm 3.0 cm Timberlake, Chemistry 7 th Edition, page 7 cm 1 2 3 4 5 cm 1 2 3 4 5 cm 1 2 3 4 5

Implied Range of Uncertainty 5 6 4 3 Implied range of uncertainty in a measurement reported as 5 cm. 5 6 4 3 Implied range of uncertainty in a measurement reported as 5.0 cm. Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 32 5 6 4 3 Implied range of uncertainty in a measurement reported as 5.00 cm.

20 10 ? 15 mL ? 15.0 mL 1.50 x 10 1 mL

Reading a Vernier A Vernier allows a precise reading of some value. In the figure to the left, the Vernier moves up and down to measure a position on the scale. This could be part of a barometer which reads atmospheric pressure. The "pointer" is the line on the vernier labeled "0". Thus the measured position is almost exactly 756 in whatever units the scale is calibrated in. If you look closely you will see that the distance between the divisions on the vernier are not the same as the divisions on the scale. The 0 line on the vernier lines up at 756 on the scale, but the 10 line on the vernier lines up at 765 on the scale. Thus the distance between the divisions on the vernier are 90% of the distance between the divisions on the scale. http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html 756

Reading a Vernier A Vernier allows a precise reading of some value. In the figure to the left, the Vernier moves up and down to measure a position on the scale. This could be part of a barometer which reads atmospheric pressure. The "pointer" is the line on the vernier labeled "0". Thus the measured position is almost exactly 756 in whatever units the scale is calibrated in. If you look closely you will see that the distance between the divisions on the vernier are not the same as the divisions on the scale. The 0 line on the vernier lines up at 756 on the scale, but the 10 line on the vernier lines up at 765 on the scale. Thus the distance between the divisions on the vernier are 90% of the distance between the divisions on the scale. 756 750 760 770 Scale 5 10 Vernier http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html

If we do another reading with the vernier at a different position, the pointer, the line marked 0, may not line up exactly with one of the lines on the scale. Here the "pointer" lines up at approximately 746.5 on the scale. If you look you will see that only one line on the vernier lines up exactly with one of the lines on the scale, the 5 line. This means that our first guess was correct: the reading is 746.5. 5 10 750 740 760 What is the reading now? 741.9 http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html

750 740 760 If we do another reading with the vernier at a different position, the pointer, the line marked 0, may not line up exactly with one of the lines on the scale. Here the "pointer" lines up at approximately 746.5 on the scale. If you look you will see that only one line on the vernier lines up exactly with one of the lines on the scale, the 5 line. This means that our first guess was correct: the reading is 746.5. 5 10 What is the reading now? 756.0 http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html

750 740 760 Here is a final example, with the vernier at yet another position. The pointer points to a value that is obviously greater than 751.5 and also less than 752.0. Looking for divisions on the vernier that match a division on the scale, the 8 line matches fairly closely. So the reading is about 751.8. In fact, the 8 line on the vernier appears to be a little bit above the corresponding line on the scale. The 8 line on the vernier is clearly somewhat below the corresponding line of the scale. So with sharp eyes one might report this reading as 751.82 ± 0.02. This "reading error" of ± 0.02 is probably the correct error of precision to specify for all measurements done with this apparatus. 5 10 http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html

How to Read a Thermometer (Celcius) 10 5 4.0 o C 10 5 8.3 o C 100 50 64 o C 5 3.5 o C

o C 10 o C 20 o C 30 o C 40 o C 50 o C 60 o C o C 1 o C 2 o C 3 o C 4 o C 5 o C 6 o C o C 5 o C 10 o C 15 o C 20 o C 25 o C o C 20 o C 40 o C 60 o C 80 o C 100 o C o C 20 o C 40 o C 60 o C 80 o C 100 o C Record the Temperature (Celcius) A B C D E 30.0 o C 3.00 o C 19.0 o C 48 o C 60. o C

Measurements Metric (SI) units Prefixes Uncertainty Significant figures Conversion factors Length Density Mass Volume Problem solving with conversion factors Timberlake, Chemistry 7 th Edition, page 40

Using Measurements MEASUREMENT Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Accuracy vs. Precision Accuracy - how close a measurement is to the accepted value Precision - how close a series of measurements are to each other ACCURATE = Correct PRECISE = Consistent Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Percent Error Indicates accuracy of a measurement your value accepted value Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Percent Error A student determines the density of a substance to be 1.40 g/mL. Find the % error if the accepted value of the density is 1.36 g/mL. % error = 2.9 % Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Significant Figures Indicate precision of a measurement. Recording Sig Figs Sig figs in a measurement include the known digits plus a final estimated digit 2.35 cm Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Significant Figures Counting Sig Figs (Table 2-5, p.47) Count all numbers EXCEPT: Leading zeros -- 0.00 25 Trailing zeros without a decimal point -- 2,5 00 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

4. 0.080 3. 5,280 2. 402 1. 23.50 Significant Figures Counting Sig Fig Examples 1. 23.50 2. 402 3. 5,28 4. 0.0 80 4 sig figs 3 sig figs 3 sig figs 2 sig figs Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Significant Figures Calculating with Sig Figs Multiply/Divide - The # with the fewest sig figs determines the # of sig figs in the answer. (13.91g/cm 3 )(23.3cm 3 ) = 324.103g 324 g 4 SF 3 SF 3 SF Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Significant Figures Calculating with Sig Figs (con’t) Add/Subtract - The # with the lowest decimal value determines the place of the last sig fig in the answer. 3.75 mL + 4.1 mL 7.85 mL 224 g + 130 g 354 g  7.9 mL  350 g 3.7 5 mL + 4. 1 mL 7.85 mL 22 4 g + 1 3 0 g 354 g Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Unit 1 Introduction to Chemistry Grade 7.pptx

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Unit 1 Introduction to Chemistry Grade 7.pptx

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