States of Matter
| state | define shape | definite volume |
| solid | yes | yes |
| liquid | no | yes |
| gas | no | no |
Book K, Chemical Building Blocks
Chapter 2, Changes in Matter
Section 1 What are the states of matter?
List items in this room for each state.
states of matter
| solid | liquid | gas |
| desk | tea | air |
States of Matter
| state | define shape | definite volume |
| solid | yes | yes |
| liquid | no | yes |
| gas | no | no |
click here for more info on states of matter
Section 4, Physical and Chemical Changes
Energy and Change
Physical change
-- alters the form of a substance but does not change it into another substance
Chemical change
-- the substance becomes another substance with different properties
Try this:
With your group do each of these tasks and classify them as either physical or chemical changes.
1. Light a candle and put it into lump of clay. Use tongs to hold an empty beaker about 1cm above the flame. What happens?
What kind of change is this? chemical
2. Crumple up a piece of paper.
What kind of change is this? physical
3. Mix about 10 mL of vinegar with one scoop of baking soda. What happens?
What kind of change is this? chemical
4. Use tongs to hold a beaker filled with ice over a beaker of hot water. What happens?
What kind of change is this? physical
Changes in matter can be explained by the effects of energy
There are many types of energy including:
thermal energy-- which comes from the movement of particles
chemical energy-- which comes from chemical bonds between atoms
mechanical energy--which is the movement of machines
magnetic energy -- which comes from magnetic fields
electrical energy -- which comes from electricity
Matter changes whenever energy is added or taken away
examples:
cooking an egg
making ice cream
boiling water
Matter changes whenever energy is added or taken away. However, in every physical change and every chemical change the total amount of energy stays the same. This is called the Law of Conservation of Energy. Energy can change form but can never be lost. example: a piece of wood contains chemical energy. When it is burned it releases thermal (heat) energy and light energy. The total amount of chemical energy equals the total amount of thermal plus light energy. No energy is gained or lost.
Physical changes due to energy
-melting -change in state from solid to liquid
(energy was added)
- freezing -change in state from liquid to solid
(energy was removed)
- vaporization - change in state from liquid to gas
(energy was added)
-evaporation -vaporization on the surface of liquid (energy was added_)
- boiling -rapid vaporization inside a liquid (energy added)
-condensation - change in state from gas to liquid (energy removed)
- sublimation - change in state from solid to gas (energy added)
If the activity above does not work click here.
If the activity above does not work click here
Chemical changes due to energy
- chemical reaction(click here)
- another name for chemical change
- all chemical reactions either absorb or release energy
examples:
-toast burning
-cake baking
-cells growing
-plant growing
endothermic reactions -- chemical reactions that absorb energy (gets cold)
exothermic reactions -- chemical reactions that release energy (gets hot)