1. Physical versus Chemical Properties & Changes
Chapter 1 – Section 3
Changes in Matter

2. Reviewing MATTER Matter: anything that has mass and takes up space
Mass – the amount of matter in something
Volume – the amount of space something occupies
Which of the following is matter?
A car?
A box?
You?

3. What is a property? CHARACTERISTIC PROPERTY:
A characteristic of a substance that can be observed and/or measured

4. What are characteristic properties good for?
We can use these properties to identify substances.
2 basic types of properties of matter:
PHYSICAL and CHEMICAL
ALWAYS the same whether object is large or small

5. Physical Property
PHYSICAL PROPERTY: A property that can be observed WITHOUT CHANGING the identity of the substance.
A feature of a substance that does NOT involve a chemical change.
Same substance, same compounds you started with.

6. Physical Property Examples: * State @ room temp (solid, liquid, gas)
* Color
* Shape
* Hardness
* Density
* Texture
* room temp (solid, liquid, gas)
* Size (mass, volume)
* Melting point
* Boiling point
* Malleability (hammer into sheets)
* Ductility (stretch into wires)
* Taste (don’t taste unknown chemicals!)
* Odor (don’t sniff unknown chemicals!)
* Luster (surface appearance)– shiny, dull
* Solubility (ability to dissolve in a
substance)
* Electrical conductivity
* Thermal conductivity (heat)
* Sound conductivity 6

7. Chemical Property CHEMICAL PROPERTY:
A property that can only be observed by CHANGING the identity of the substance.
Characteristics that indicate if a material can undergo a certain chemical change.
A property of matter that describes its ability to be involved in chemical reactions.
Chemical properties can ONLY be observed AS the substances are changing into different substances.

8. Chemical Property Examples:
* Flammability (Combustibility)– ability to burn
* Ability to rust from oxygen
* Reactivity with water or vinegar
* Toxicity- how dangerous the material is
* Radioactivity- does the material give off radiation
* Sensitivity to light- how sensitive the material is when placed under a light or the sun 8

9. Physical Changes
Physical changes are those changes that DO NOT result in the production of a new substance. If you melt a block of ice (frozen H2O), you still have H2O at the end of the change.   

10. Physical Changes
If you break a bottle, you still have glass.  Painting your nails will not stop them from being fingernails.  Some common examples of physical changes are: melting, freezing, condensing, breaking, crushing, cutting, and bending.

11. Physical Changes
Affects one or more physical properties of a substance, but not chemical properties or identity of a substance (appearance affected, but not composition)

12. Physical Changes
Some, but not all physical changes can be reversed. You could refreeze the water into ice, but you cannot put your hair back together if you don’t like your haircut!

13. Chemical Changes
Chemical changes, or chemical reactions, are changes that result in the production of another substance.
Occurs when 1 or more substances change into entirely new substances with different characteristic properties.
Cannot reverse chemical changes using physical means, sometimes cannot reverse at all

14. Chemical Changes
Common examples of chemical changes that you may be somewhat familiar with are: digestion, respiration, photosynthesis, burning, and decomposition. 

15. FLAMMABILITY: A material’s ability to BURN in the presence of OXYGEN
Chemical Changes
FLAMMABILITY: A material’s ability to BURN in the presence of OXYGEN

16. Chemical Changes
When you burn a log in a fireplace, you are carrying out a chemical reaction that releases carbon.  When you light a candle at home, you are carrying out a chemical reaction that produces carbon (soot) and carbon dioxide gas. 

17. Chemical Changes
REACTIVITY: How readily (easily) a substance combines chemically with other substances.

18. Clues to Chemical Changes
Dramatic color change (can’t use this alone!) Fizzing, foaming (new production of gas) Precipitate (new production of solid substance) Production or use of energy (light, heat) Production of sound, odor

19. Physical or Chemical Change?
QUIZ TIME

20. Physical or Chemical Change?
Painting Wood
PHYSICAL

21. Physical or Chemical Change?
Digestion of food
CHEMICAL

22. Sugar dissolving in water PHYSICAL
Physical or Chemical Change?
Sugar dissolving in water
PHYSICAL

23. Iron turning red when heated PHYSICAL
Physical or Chemical Change?
Iron turning red when heated
PHYSICAL

24. Physical or Chemical Change?
Evaporation
PHYSICAL

25. A pond freezing in winter PHYSICAL
Physical or Chemical Change?
A pond freezing in winter
PHYSICAL

26. Physical or Chemical Change?
Melting ice
PHYSICAL

27. Physical or Chemical Change?
Cutting wire
PHYSICAL

28. Physical or Chemical Change?
Painting fingernails
PHYSICAL

29. Physical or Chemical Change?
Cutting fabric
PHYSICAL

30. Physical or Chemical Change?
Baking muffins
CHEMICAL

31. Physical or Chemical Change?
Shattering glass
PHYSICAL

32. Decomposition of old leaves CHEMICAL
Physical or Chemical Change?
Decomposition of old leaves
CHEMICAL

33. Physical or Chemical Change?
Wrinkling a shirt
PHYSICAL

34. Physical or Chemical Change?
An old nail rusting
CHEMICAL

35. Physical or Chemical Change?
Burning Paper
CHEMICAL