Physical and Chemical Changes

1
Physical and Chemical Changes
2
Physical and Chemical Properties
Everything around us has physical and chemical
properties.
3
Physical Properties

• Characteristics you can observe without changing
  the substance into something new.
• Use your senses to describe
• state of matter
• measurement

4

• Use your senses How does it look, smell, sound,
  feel, taste (dont taste it unless the teacher
  says its ok)

5

• What state of matter is it? (solid, liquid, or
  gas)

6

• Measure it.mass, weight, volume, length, width,
  height, density, temperature, magnetic?

7
Physical Properties

• List as many physical properties as you can

Color
Temperature
Feel
Smell
State
Weight
Length
Density
8
Chemical Properties

• Characteristics that you can only observe by
  changing the substance into something new.
• You cant always tell chemical properties just by
  looking

• Will it burn, explode, react with other elements?

9
Chemical Properties

• List as many chemical properties as you can

Will it burn
Will it explode
Can it react with other things
10
Physical and Chemical Changes
Matter around us can undergo changes. Physical
Changes Chemical Changes
11
Physical Change

• A change in which the form or appearance of
  matter changes but not its composition
• Change of state
• Change of shape
• Dissolving

12
Physical Changeschanging state
melting solid to liquid
condensation gas to liquid freezing liquid
to solid sublimation solid to
gas vaporization liquid to gas
deposition gas to solid
13
Changes in States
14
Physical Changeschange of shape
Matter can change shape cutting tearing grindi
ng crumpling bending
15
Physical Changesdissolving
When you mix or dissolve one thing into another,
it is a physical change
16
Chemical Change

• A change in which the composition of matter
  changes and new substances are formed
• It cannot be turned back into the original
  substance

17
Chemical Change

• Signs that a chemical change may have taken place
• Color change
• Absorption or release of energy
• Odor
• Formation of gases or solids
• Cant be reversed

18
Chemical Changes
Iron oxygen and water rust
silver oxygen and water tarnish
19
Chemical Changes
Burned wood
Cooked food
20
Chemical Changes
Leaves turning in fall
Spoiled food
21
Chemical Changes
Lightning bug
Antacid tablet
22
Physical or Chemical
orange
Orange juice
Orange cake
Chemical
Physical
Copper jewelry
Statue of Liberty
copper
Physical
Chemical
23
Law of Conservation of Mass
The total mass of matter before and after a
physical or chemical change is the same. Matter
cannot be created or destroyed The particles
inside the matter rearrange to form new substances
24
Law of Conservation of Mass

• Even though it appears that part of the candle
  disappears, it is just turned into a gas.
• proven by
• Antoine Lavoisier

25
Directions Take out all of the laminated cards.
Find the Physical Change and Chemical Change
cards. Using the posterboard, put the physical
change card on the left side and the chemical
change card on the right side. Now
take out the remaining cards and lay them out in
front of you. As a table, look at the picture and
read the description on the back. Decide whether
your group thinks each one is a physical change
or a chemical change. Once everyone has agreed,
place the card on the correct side of the poster.
Record your answers in the table on youR
worksheet by placing an X in the physical or
chemical change box