Compounds & Elements

Compounds and Elements

1. Compounds And Elements
Objectives:
3.3Describe a pure substance as a
compound or an element, after
conducting an experiment.
3.4Analyze a compound.

2. Classification:
Everything in the world that has a mass
is called “matter”
Matter can be classified as:
Matter
Pure Substance Mixture
Element
Ex. gold
Compound
Ex. water
Hetero-
geneous
Mixture
Homo-
geneous
Mixture

3. Matter:
anything that takes up space & has a
mass
Ex.a desk
Ex.pizza
Ex.silver necklace
Ex.oxygen

4. Mixture:
combinations of two or more substances
that are not chemically combined (mixed)
Easily separated
Ex.fruit salad
Ex.sugar in coffee
Pure Substance:
composed of a single substance with the
same properties throughout
Ex.water
Ex.table salt

5. simplest form of matter
cannotbe separated or broken down
into simpler substance
Ex. Oxygen
Ex. Aluminum
Ex. Gold
Ex. Copper
A pure substancecan be further broken
down into an elementor a compound……
Elements:

6. substance made of two or more
different elements
canbe separated into simpler
substance
Ex. Water (H
2O)
Ex. Carbon dioxide (CO
2)
Ex. Sugar (C
6H
12O
6)
Ex. Salt (NaCl)
Recall, a pure substancecan be further
broken down into an elementor a compound
Compounds:

7. NOTE:
With chemical reactions, you may
be able to go from an element to
compound & vice versa!!!
Element Compound
H
O
Ex.oxygen &
hydrogen
Ex.water
(H
2O)
H
O
H H

8. Recall, a mixturecan be further broken
down into a homogeneous mixture or a
heterogeneous mixture……
Homogeneous Mixture:
Mixture that looks uniform throughout
or like one substance
Ex.milk in coffee
Ex.sugar dissolved in water
Heterogeneous Mixture:
mixtures that are not uniform
can see individual parts
Ex. salad
Ex.chocolate chip muffin

9. State whether the following
are examples of an
elementor a compound.
A gold ring
Rust (Fe
2O
3)
Carbon monoxide (CO)
Aluminum Foil
Calcium
element
compound
compound
element
element

10. State whether the following are
examples of an elementor a
compound or a mixture
A blueberry muffin
Chunky Soup
Salt (NaCl)
Helium
Water (H
2O)
mixture
mixture
compound
element
compound

11. Element
Compound
Mixture
Compound
State whether the following pictures
represent an elementor a
compound or a mixture

12. Which statement best
describes a compound.
A)A pure substance that has a high
melting point.
B)A mixture that is formed by two or
more elements.
C )A pure substance that is formed by
two or more elements.

13. Reactions:
Chemical Reactions can combine
elements to make compounds
(synthesis reaction)
OR
Chemical Reactions can break apart
compounds into its elements
(decomposition reaction )

14. Synthesis Reaction:
Makes a new substance
Sign of a chemical change
Increase in mass
Ex.
Ex.
If you see mass,
the ONLYthing
you know is that a
compound was
made!!!
+ 
+ 

15. Decomposition Reaction:
Two or more substances produced
Sign of a chemical change
Decrease in mass
Ex.
Ex.
If you see
mass, the
ONLYthing
you know is
that you
started with
a
compound!
+
+

16. You a leave a 2g copper penny outside.
Over time, the penny becomes green in
color & its mass is now 2.5g.
Which statements below are true?
A) A chemical change occurred
B) A physical change occurred
C) A compound was made
TRUE
TRUE
D) An element was made

17. You have 5g orange powder which you
heat. As the powder is heated you
noticed that a gas is given off & a silver
liquid is produced. After heating you only
have 1g of the orange powder left.
Which substance was definitely a
compound? Why?
orange powder
decrease in mass production of two
substances

18. A grey colored solid is
heated. The following
observations were recorded
Before HeatingAfter Heating
State solid solid
Color grey black
Texture smooth granular
Mass 1.75g 2.5g
What statement is DEFINITELY true?
A) The solid after heating is an element
B) The solid after heating is a compound
C ) The solid before heating is an element
TRUE

19. A)The white powder could be an element
In a lab you heat 50g of a white powder
in an open container. Over time, you
obtain a yellow substance with a mass
of 65g.
Which statement is FALSE?
B)The white powder could be a compound
C)The yellow substance could be an element
D)The yellow substance could be a compound

20. Mixture:
2 or more components brought together that
can be separated physically
Pure Substance
A single substance with the same properties
throughout
Element
Simplest form of matter that can not be
broken down
Compound
2 or more different elements chemically
combined

21. To identify elements or compounds:
If mass increases, you know that
you have madea compound
If mass decreases, you know that
you started with a compound

22. Molecule
A molecule is a group of 2 or more
chemically bonded atoms.
A compound is a type of molecule.
E.g Carbon Monoxide –CO
E.g. Oxygen gas -O
2
Q. Is NaCl a compound or a molecule?
Q. Is H
2 a compound or a molecule or
an element?