INTEGRATED SCIENCE GRADE 7 YEAR 2023.pptx

science grade 7 NOTES

1. INTEGRATED SCIENCE GRADE 7 – 2023 BY MR. MURAGE

2. STRAND 1: SCIENTIFIC INVESTIGATION Pure Sciences are studied as separate science learning areas. Integrated science is when two or more pure sciences are combined. Integration in science involves a collaboration or unity among a number of pure sciences that were traditionally taught separately. Pure Sciences are what we call Components of Integrated Science. Components of Integrated Science are: Chemistry Physics Biology

3. LABORATORY SAFETY A hazard is something that is a danger or that can cause damage. Examples of common hazards in the laboratory are: Flammable substances. Corrosive chemicals Toxic substances. Carcinogenic substances Radioactive substances. Examples of common laboratory accidents include burns and scalds , cuts, eye, injuries, ingestion of harmful substances .

4. BASIC SCIENCE SKILLS Basic science skills include: Observation Prediction Manipulation Measurement Classification Conclusion Communication There are seven basic SI units: metre, kilogram, second, ampere, Kelvin etc . Derived units are formed by combining SI basic units e.g. Square metre(for area), cubic metre(for volume), Kilograms/cubic metre(for density). Ways of communicating science information includes peer-reviewed journals, conferences and popular media. Learners can communicate science information to classmates using tables, charts, graphs, slides, computer applications.

5. LABORATORY APPARATUS AND INSTRUMENTS Apparatus and instruments used in the lab include: Volume measuring apparatus such as graduated cylinder, beaker, volumetric flask, conical flask, burette, pipette. Mass measuring apparatus such as beam balance and electronic balance. Time measuring apparatus such as stop watch and clock. Length measuring apparatus such as tape measure, metre rule and Vernier calipers. Temperature measuring apparatus such as a thermometer. Heating apparatus such as Bunsen burner, tripod stand, wire gauze, crucible and lid, evaporating dish, boiling tube. Magnification instrument such as light/ optical microscope and hand lens.

6. Some of the safety pre-cautions in the laboratory include: Know locations of laboratory safety showers, eyewash stations, and fire extinguishers. The safety equipment may be located in the hallway near the laboratory entrance. Do not carry a beaker by its side. Wash the glass apparatus immediately after use as it will be harder to clean them later. Any apparatus that is broken should either be repaired if possible or disposed off to avoid unnecessary accidents. Fragile laboratory apparatus should be handled with care to avoid unnecessary breakages. Always use two hands when carrying an apparatus made of glass. One hand should always be under the glass for support.

7. ASSESSMENT Explain the meaning of integrated Science. State the components of integrated science. List any six common hazards in the laboratory. How are derived units formed? How are basic skills in science important in daily life? State any three basic laboratory safety rules and regulations. Name any two apparatus used for measuring length.

8. STRAND 2: MIXTURES, ELEMENTS AND COMPOUNDS A mixture is a physical combination of two or more substances that are not chemically combined. There are four main types of mixtures namely: Solid-solid mixture Liquid-liquid mixture Solid-liquid mixture Gaseous mixture

9. DETERMINING MELTING POINT OF PURE AND IMPURE SUBSTANCES The constant point at which a substance melts is known as melting point. Melting point can be used to distinguish between pure and impure substances. Impurities are substances that are present in small quantities in another substance and make it dirty or contaminated. Impurities have an effect of lowering the melting point of a substance.

10. DETERMING BOILING POINT OF PURE AND IMPURE WATER Constant temperature which a substance boil is known as its boiling point. Boiling point can be used to distinguish between pure ad impure substances. Small impurities in water can slightly increase its boiling point. Impurities have an effect of increasing boiling point of substances while lowering the melting points. Pure substances contains only one type of matter and melts or boils at a constant temperature. Impure substances contains more than one type of matter and varies the boiling points and melting points.

11. SEPERATING MIXTURES USING DIFFERENT METHODS Different mixtures can be separated using the below methods: Decantation Filtration Crystallization Simple distillation Use of a magnet Sublimation Paper chromatography Solvent extraction

12. APPLICATION OF DIFFERENT METHODS OF SEPARATING MIXTURES Mixtures can be classified as homogenous or heterogenous. Method used to separate mixtures depend on the physical properties of the components in the mixture. We have seen earlier that impurities lower the melting points of substances and increase their boiling points. Applications of separating mixtures in day-to-day life include: Fractional distillation of liquid air. Crude oil refining. Extraction of oil form nuts.

13. ACIDS, BASES AND INDICATORS Acids are substances with sour taste while bases have a bitter taste. Some acids are tea, coffee, sour milk, fresh milk, tomato juice, lemon juice, orange juice, soda and vinegar. Examples of bases are soap, detergent, wood, ash, baking powder, bleach and toothpaste. Indicators are substances that show particular colour in an acid and a different colour in base. Flower extracts do not give consistent colours hence they are unreliable indicators. Strength of an acid and base is measured using universal indicator and a PH scale.

14. APPLICATION OF ACIDS AND BASES Using lime to raise soil PH. Removing stains on substances. Removing scales in boilers. Using antacids to relieve stomach upsets.

15. ASSESSMENT 1.Differentiate homogenous mixture from heterogenous mixture 2. Explain why melting and boiling points can be used to determine purity of substances. 3. State any two applications of separating mixtures in day-to-day life. 4. Differentiate acids from bases 5. Give two examples of acid-base indicators 6. State 3 applications of acids and bases in real life.

16. STRAND3: LIVING THINGS AND THEIR ENVIRONMENT REPRODUCTION IN HUMAN BEINGS Menstruation is the process of shedding the thick lining of the uterus on a regular monthly basis in women. It is also referred to as monthly period. Menstruation begins at puberty, usually two years after breasts and pubic hair start to develop. Average girl starts menstruation at 12 years, but varies from girl to girl. Menstrual cycle is the monthly series of changes a woman’s body goes through in preparation of possibility of pregnancy.

17. Menstrual cycle is divided into four phases: Menstruation – The period where the internal lining of uterus is shed through the vagina. It is the first phase of the menstrual cycle and lasts 3-7 days. Follicular – When several eggs mature inside cysts or follicles. Ovulation – This is when an egg is released from the biggest follicle and travels through the fallopian tube, where it can be fertilized. It lasts about 24 hours and happens right in the middle of your menstrual cycle. Luteal phase – This is when the lining of the uterus is thick and prepared to support pregnancy. If pregnancy does not occur, uterine lining is shed during menstruation and the cycle starts again.

18. CHALLENGES RELATED TO MENSTRUAL CYCLE Lack of sanitary towels Head aches or back aches Acne or pimples Mood swings Menstrual cramps Irregular periods Excessive bleeding

19. FERTILISATION AND IMPLANTATION Human fertilization is the fusion union of a human egg and sperm to form a fertilized egg. Implantation is the process in which a developing zygote attaches itself to the wall of the uterus and remains attached to itself to the wall of the uterus and remains attached to it until birth.

20. HUMAN EXCRETORY SYSTEM – SKIN AND URINARY SYSTEM Skin is the largest body organ as it covers the whole body surface and even continues into many body openings like ears, nostrils and mouth. External parts of the skin are epidermis (upper layer of the skin), sweat pole and the hair (the part of the hair that is exposed on the skin surface). The waste products excreted through the skin are water and salts.

21. URINARY SYSTEM Urinary system consists of: kidneys, blood vessels(renal artery and renal vein, ureter, bladder and urethra. Two kidneys are bean-shaped and red-brown in colour and are enclosed in transparent membrane attached to the abdomen. Kidney is major organ through which urine is formed and excreted. It purified the blood that passes through it, producing urine as waste product. Ureter carries urine from bladder. When bladder is full, sphincter muscles relax forcing urine out through urethra.

22. Main functions of urinary system are: Purifying blood and producing urine as waste. Excretion of wastes (urine) form the body Maintaining blood volume and pressure Regulating body PH.

23. ASSESSMENT What is the duration of menstrual cycle in humans? Explain any two challenges related to menstrual cycle. Distinguish between process of fertilization and implantation in humans. Briefly explain the role of the skin in excretion? Illustrate how the urinary system plays an important role in blood purification

24. STRAND 4: FORCE AND ENERGY Static charges occur when two surfaces touch or are close to each other and charges move from one object to another. One object will have a positive charge and the other negative charge.

25. When some materials are rubbed against each other, static charges are created. Static charges created are responsible for the attraction experienced when small pieces of papers are placed next to the rubbed materials. Static charges remain on an object until they flow into the ground, into another object.

26. EFFORTS OF FORCE BETWEEN CHARGED OBJECTS Rubbing an ebonite rod with wool gives it a negative charge. A negatively charged ebonite rod is attracted by the glass rod. Rubbing cellulose acetate with silk gives it a positive charge. A positively charged acetate rod is repelled by the glass rod. Like charges repel each other while unlike charges attract each other.

27. USES OF STATIC CHARGES IN DAILY LIFE It is useful for charging non-conductors of electricity. Used in printers and photocopiers where static electric charges attract the ink or toner to the paper. Other uses include paint sprayers, air filters and dust removers. Lightning is a powerful but dangerous example of static electricity. Lightning can damage buildings, trees and even harm people. If you think you may be carrying static charges, touch a metal object to discharge the electricity. Lightning arrestors should be fitted on tall buildings.

28. ELECTRICAL ENERGY Sources of electricity include hydro-electric power, geothermal, solar and wind power. Circuit refers to the path that an electric current flows. It is possible to set up a simple electric circuit using dry cells, a light bulb ad insulated wires. Simple electric circuits can be set up in series and parallel using dry cells, bulbs, ammeters and voltmeters. Materials can be classified as conductors and non-conductors of electricity. Conductors of electricity are materials that allow electric current to flow freely through them e.g. silver, copper, mercury, aluminum, gold.

29. Non-conductors of electricity are materials that do not allow electric current to flow freely through them e.g. plastic, rubber, wool, wood, paper, fur, silk, glass. Electrical appliances are devices or instruments that use electricity and have been designed to perform a specific function e.g. refrigerator, Television, cooker, toaster, blender, iron box, water, heater, microwave. Electricity is used for lighting, heating, cooking, refrigeration, operating electrical appliances and systems.

30. MAGNETISM Materials attracted by magnets are called magnetic materials and those not affected by magnets are called non-magnetic materials . Magnetic materials include iron, steel, cobalt, nickel and chromium. Examples of non-magnetic materials are paper, glass, brass, copper, aluminium and wood. Each magnet has two poles : North pole and south pole. Unlike poles attract while like pole repel. Magnets are used in devices such as electric motors, magnetic compasses, refrigerators, doorbells, dynamos, loud speakers, microphones.

31. ASSESSMENT 1.What is force? 2. Give two uses of static charges in daily life. 3. Give four sources of electric energy. 4. Explain two ways in which you can set up simple electric circuits. Differentiate conductors and insulators. Give 3 uses of magnetism.

32. I wish you a MERRY CHRISTMAS and a HAPPY NEW YEAR 2024. May the Christmas Season bring only happiness and joy to you and your family.