1. Properties & Changes
Textbook Section 14.3

2. What’s A Property? A quality belonging to something In Chemistry:
Characteristic
A quality belonging to something
In Chemistry:
Usually tied to what phase the sample is in

3. Two Types of Properties: PHYSICAL Properties
(def.) a change that can be observed or measured without changing what the sample is made of
The LOOK or FEEL of something
Used to IDENTIFY a sample

4. Two Types of Properties: PHYSICAL Properties
Examples: Color, Malleability, Elasticity… What else?

5. Two Types of Properties: CHEMICAL Properties
(def.) a property that tells you how or if a substance has the ability to react with others
Ability to change one thing to something else
Used to IDENTIFY a sample
Ask Yourself: Has the sample changed??

6. Two Types of Properties: CHEMICAL Properties
Is the sample changed?? YES!! Copper is reacting with carbon dioxide & water to create patina

7. Two Types of Properties: CHEMICAL Properties
Examples: Flammability, Combustion Temps, Toxicity, Reactivity in Water…

8. Distinguishing Between The Two
Aluminum is silvery-white. A: Physical Property B: Chemical Property

9. Distinguishing Between The Two
Calcium can do this in water. A: Physical Property B: Chemical Property

10. Distinguishing Between The Two
Oak wood has a density of 0.8 kg/m3 A: Physical Property B: Chemical Property

11. Two Types of Changes: PHYSICAL Changes
(def.) a change that DOES NOT affect the chemical composition of a substance
A change in a physical property or phase
Easily reversible

12. Two Types of Changes: CHEMICAL Changes
(def.) change in which one or more substances turn into different substances
Atoms rearrange themselves
Bonds between atoms are broken and new ones form

13. Two Types of Changes: CHEMICAL Changes
Also called a CHEMICAL REACTION
Signs
Not easily reversible
Formation of a new substance with its own properties

14. Signs of a CHEMICAL Change
Formation of a gas - Bubbles
Release/Absorption of heat
Color Change (different than original)

15. Signs of a CHEMICAL Change
Formation of a solid – Precipitate
Light – Release of Energy

16. Distinguishing Between The Two
Practice:
Each circle is an atom.
Different colored circles are different elements
Connected circles are molecules.

17. Distinguishing Between The Two
Gold being melted to form bars A: Physical Change B: Chemical Change

18. Distinguishing Between The Two
Wood burning in a fireplace A: Physical Change B: Chemical Change

19. Distinguishing Between The Two
Clay being sculpted A: Physical Change B: Chemical Change