1. Physical and Chemical Changes

2. Kinetic Theory of Matter
THEORY OF KINETIC ENERGY
A. ATOMS ARE ALWAYS MOVING
B. THE MORE ENERGY ADDED TO THE ATOMS, THE FASTER & FARTHER APART THEY MOVE

3. PHYSICAL OR CHEMICAL CHANGE
Physical Changes
Matter is always changing form, size, shape, color, etc. There are 2 types of changes that matter undergoes.
PHYSICAL OR CHEMICAL CHANGE
I. Physical Changes: a change of matter without changing the identity of the substance. IN OTHER WORDS
A CHANGE IN STATE
A CHANGE IN SIZE, SHAPE, MASS
DOES NOT CHANGE THE CHEMICAL MAKE UP OF THE MATTER
YOU HAVE WHAT YOU STARTED WITH JUST IN A DIFFERENT FORM

4. Examples of Physical Changes
Verbs used to describe physical changes – grind, dissolve, erode, rip, tear, break, phase change (melt, freeze, condense, etc)

5. Other Physical Change Examples
PAPER TORN INTO PIECES
SUGAR DISSOLVED INTO TEA
SALT DISSOLVED INTO WATER
NAILS OR HAIR CUT

6. Phase Changes are PHYSICAL PHYSICAL!!!!!
Types of Phase Changes:
1. Melting
2. Freezing
3. Evaporization
4. Condensation
5. Sublimation
6. Deposition
ALL phase changes are caused by ADDING or TAKING away energy!!!

7. MATTER CHANGES FROM ONE STATE OF MATTER TO ANOTHER
WHEN HEAT (ENERGY) IS ADDED
WHEN HEAT (ENERGY IS TAKEN AWAY

8. DRAW THIS DIAGRAM IN YOUR NOTES!!!!

9. CHANGING STATES DOES NOT CHANGE THE CHEMICAL MAKE UP OF THE MATTER
YOU HAVE WHAT YOU STARTED WITH JUST IN A DIFFERENT FORM
ICE  WATER  WATER VAPOR
H2O H2O H2O

10. WHEN MOLECULES MOVE FASTER, THEY PRODUCE MORE FRICTION AND THEREFORE MORE HEAT. THEY SPREAD FARTHER APART & EXPAND
WHEN MOLECULES MOVE SLOWER, THEY CAUSE LESS FRICTION AND THEREFORE LESS HEAT & CLOSER TOGETHER & CONTRACT

11. Melting 1. MELTING – matter changing FROM A SOLID TO A LIQUID.
Energy is added
When more heat (energy) is added to matter the particles move faster till the bonds break.
Decrease density except ice to water.

12. Evaporation/Vaporization
Matter changing FROM A LIQUID TO A GAS AT THE SURFACE
ENERGY IS ADDED TO SURFACE OF LIQUID
THE PARTICLES AT THE SURFACE MOVE FASTER breaking bonds.
Decreases density.
VAPORIZATION- a
general term for any
substance changing to
a gas.

13. Boiling 3. BOILING EX: pan of liquid on the stove
matter changing FROM A LIQUID TO A GAS ALL THROUGHOUT THE LIQUID
ENERGY IS ADDED TO ALL OF LIQUID
PARTICLES MOVE FASTER ALL THROUGH THE LIQUID
SOME PARTICLES MOVE FAST ENOUGH TO CHANGE TO GAS WHILE THEY ARE IN THE MIDDLE OF THE LIQUID
DENSITY DESCREASES
Water boils at 212 F, 100C.
EX: pan of liquid on the stove
VAPORIZATION- a general term
for any substance changing to a gas.

14. VAPORIZATION!!!
Remember that vaporization is a general word for any substance changing to a gas.
Boiling, evaporation, and sublimation are ALL examples of vaporization!!!

15. Condensation 4. CONDENSATION Matter CHANGING FROM A GAS TO A LIQUID
ENERGY IS REMOVED
THE PARTICLES MOVE SLOWER
THE ATTRACTION BETWEEN THE PARTICLES BEGAN TO PULL THE PARTICLES CLOSER TOGETHER & THE MATTER TURNS INTO A LIQUID
DENSTITY INCREASES
Ex: dew in the lawn, water running down mirror, ring on table under glass.

16. Freezing FREEZING CHANGING FROM A LIQUID TO A SOLID ENERGY IS REMOVED
THE PARTICLES MOVE EVEN SLOWER
THE ATTRACTION BETWEEN THE PARTICLES BEGAN TO PULL THE PARTICLES CLOSER TOGETHER & THE MATTER TURNS INTO A SOLID
Increase density.
Water freezes at 32 F, 0 C
EX: water to ice, wax or chocolate hardening

17. SOLIDIFICATION!!!!
Solidification is a general word for any substance changing to a solid.
Freezing and deposition are examples of SOLIDIFICATION!

18. Sublimation 5. Sublimation: matter changes straight
from a solid to a gas!!!!
Heat added rapidly
Molecules speed up and spread out rapidly
decrease density
Examples of Sublimation:
dry ice, shrinking ice in a
freezer, air freshener.

19. Deposition
-Deposition- when matter changes from a gas directly to a solid.
-Heat is taken away rapidly
-Density increases
-Molecules slow down and get closer together.
Examples:
Snowflakes,
frost on a wind shield

21. WHAT HAS TO HAPPEN FOR THESE CHANGES OF STATES TO OCCUR?

22. Bellringer 2: All phase changes are: a. physical properties
b. physical changes
c. Chemical properties
d. chemical changes
Condensation is:
a. Liquid to gas
b. Gas to solid
c. Solid to gas
d. gas to liquid

23. Let’s Sing!!!! Phase changes are physical, physical…
Melting is physical…. Freezing is physical.
BOYS: Let me see some condensation.
GIRLS: (in high pitch voice) It’s physical.
BOYS: Let me see some sublimation.
Boiling is physical… Boiling is physical…
BOYS: Let me see some deposition.
GIRLS: (in high pitch voice) It’s physical
BOYS: Let me see some evaporation.

24. Chemical Changes
The other way that matter can be changed is call a CHEMICAL CHANGE.
II. CHEMICAL CHANGE – occurs when 2 or more substances are combined into entirely new substance with all new properties. CANNOT CHANGE IT BACK!!!!!

25. Chemical Change Verbs
Chemical Change Verbs: rusting, rotting, curdling, burning, cooking, light sensitivity, digesting, tarnishing.

26. Chemical Changes SOME SIGNS OF A CHEMICAL CHANGE FIZZES OR BUBBLES
COLOR CHANGE
HEAT GIVEN OFF
LIGHT GIVEN OFF
ODOR
HEAT REQUIRED FOR REACTION
NEW SUBSTANCE FORMED
Precipitate (solid)
Precipitate (gas bubbles)

27. CHEMICAL CHANGE EXAMPLES
BAKING BREAD – NO LONGER HAVE FLOUR, EGGS, MILK, YEAST
ALKASELTER
BAKING SODA & VINEGAR
RUST
TARNISH