Chemistry Review – Answer Key
Chemistry Review
1. Identify and describe intrinsic properties of matter. Include the definition for intrinsic property and at least
2 examples.
 Intrinsic properties are either physical or chemical properties of a substance. They are properties
that do not change even if the size of the substance changes.
Examples:
Physical – no new substance is formed
Chemical – new substances are formed
Density
Rusting
Magnetism
Burning
Melting/boiling temperature
Exploding
Solubility (dissolves in water)
Reacts with acid to form bubbles
Conducts (moves) electricity
2. You have 4 liquids (Red, yellow, blue and green). Red has a density of 2.0, yellow has a density of 0.4, blue
has a density of 1.0, and green has a density of 0.8. Sort the liquids according to density. A 5th liquid, “X”
has a density of 0.6 than blue, but more dense than yellow. Where would liquid “X” fit?
“X” would fit between the
yellow and green layers
3. You have 3 liquids: water, glycerin, and oil. Glycerin is more dense than water, and oil is less dense than
water. If mixed together, in what order with these liquids be layered in a cylinder?
Oil – least dense
Water
Glycerin – most dense
4. You are given a white mystery substance that you think is either white sand or salt. What property could
you use to identify your substance? Explain how you would test this.
 Solubility (dissolves in water). Salt would dissolve, sand would not.
5. Describe two physical properties that could help you separate substances out of a mixture
Property
How it could be used
Magnetism
Something attracted to a magnet could be pulled out with a magnet
Solubility
Something that dissolves could go into a liquid, go through a filter and
other things would be stuck behind
Density
Some things float and others sink, you could add water
6. What is the difference between an element and a compound? Draw a picture of each.
Element: made of one kind of atom
Compound: made of one kind of molecule
(can be a solid, liquid or gas)
(can be a solid, liquid or gas)
Continued on next page
7. Describe what particles in solids, liquids and gas are doing. In your answer include the spacing, attraction,
motion and energy of each state of matter. Also include a diagram of each state of matter. Describe what
happens to make a liquid change to a gas.
Spacing
Motion
Attraction
Energy
Thermal and
kinetic
Solid
Touching
Vibrate in same
position
VERY attracted
Least energy
Liquid
Very close
Slide past each other
Attracted enough to
stay together
Gas
Spread apart
Moving freely
everywhere
Weak attraction



Most energy
As heat is added to a solid, the particles vibrate faster and faster until they break free from the
positions they are stuck in and start to move around each other. When that happens, the solid has
melted and the particles are doing what liquid particles do.
As heat is added to a liquid, the particles move faster and faster until they completely break free
from each other and spread out as much as possible. When that happens, the particles are doing
what gas particles do.
The less energy particles have, the more attracted to each other they are.
Continued on next page
8. In a chemical reaction, you start with reactants and end with products. How does the mass before a
reaction compare to the mass after a chemical reaction?
 There are the same number and kinds of atoms in the reactants before a chemical reaction as there are
in the products after a chemical reaction.
 No atoms were created or destroyed, so the mass before and after would be the same.
Reactants:
Products:
1 Carbon (black)
4 Hydrogen (white)
4 Oxygen (red)
1 Carbon (black)
4 Hydrogen (white)
4 Oxygen (red)
9. Vinegar and baking soda are put together in a sealed plastic bag. At first they are not mixed. Then the bag
is tipped and bubbles form as they mix, plus the bag expands. What happens to the mass in the bag? Give
evidence to support your answer.
 Since the bag is sealed, it is a closed system where no atoms or molecules can get in or out so all
the atoms before and after the reaction are still there and the mass stays the same, even though
the bag expands (has more volume) because the reaction produced carbon dioxide, which is a gas
that spreads out as much as possible.