1. Chapter 3.3 Physical and Chemical Changes

2. Physical/Chemical Change Review
Physical Change:
No new substance formed
Easily reversible
May change in size, shape or state
Chemical Change:
New substance is formed
Not easily reversible
May see:
Heat given off
Colour change
Bubbles (gas) given off

3. How is energy involved?
All changes in matter involve changes in energy
Energy is either released or absorbed
Energy is often in the form of heat but could also be in the form of light or sound
If energy is released = exothermic
Exo = exits
If energy is absorbed = endothermic
Endo = into

4. Exothermic vs. Endothermic
Exothermic – RELEASES energy
Endothermic – ABSORBS energy
Explosion
Burning wood in a camp fire
Battery running in your IPod
Magnesium metal burning in oxygen
Chemical cold pack (NOT one you have to put in the freezer)
Melting an ice cube
Cooking an egg
Recharging a rechargeable battery (energy goes in)

5. Assignment… Ch. 3 Review: pg. 106-107 #1-4, 7-9, 11, 12, 14-20
More Practice….
Textbook Questions:
3.1 Review: pg. 83 #1-4 & 6
3.2 Review: pg. 95 #2-6
3.3 Review: pg. 105 # 1, 2, 4, 5, 6