1. 1. Which of the following is an example of a physical change?
A. dissolving salt into water
B. hard-boiling an egg
C. burning wood into charcoal
D. rusting iron
2. Which of the following is an example of a chemical change?
A. ice melting
B. pounding gold into a coin
C. paint fading
D. a puddle of water evaporating
3. A chemical change occurs whenever
.
A. substances are mixed
B. objects change shape
C. hot objects melt
D. new substances form
4. A chemical change can only be reversed by
change.
A. a chemical
B. a physical
C. both a physical and a chemical
D. a phase

2. Review
• Mixtures
• Heterogeneous
• Homogeneous
• Separation of mixtures

3. Chemical Reactions
◙Chemical equations represent
chemical reactions
◙Shows two things:
◙What you start with
◙What you end up with

4. Chemical Reactions
Reactants- substance(s)
you start with
Left side of arrow ()
Products- substance(s) you
end up with
Right side of arrow ()

5. Chemical Reactions
▓Fe + S  FeS
Reactants
Product
▓The properties of iron sulfide
are different from iron and
sulfur

6. Signs of a Chemical Reaction
Products have different
properties than the reactants
Color change
Gas formation
Solid precipitate forms
Transfer or release of energy

7. Conservation of Matter
In a chemical
reaction, atoms rearrange
New products form
Is matter destroyed?
No!!!!!!!

8. Conservation of Matter
☻Find the mass
of the reactants
☻Reactants- all
the substances
that take part in
the reaction
Light
Stick
Plastic tube
Liquid 1
Glass tube
Liquid 2

9. Conservation of Matter
☺Find the mass
of the products
☺Products- all
the substances
formed, new
and/or existing
Light
Stick
Plastic tube
Broken glass
New liquid

10. Conservation of Matter
In any chemical
reaction, no mass is gained
or lost
Mass of the reactants = the
mass of all the
products, seen or unseen