1. What’s the MATTER: Classify Changes of Matter

2. Matter, Classify Changes of Matter At the conclusion of our time together, you should be able to:
Characterize various changes of matter
Recognize that a change of state in matter is a physical change

3. Physical Change Physical
A change in matter from one form to another without changing its chemical properties
(most can be reversed)
No change in atoms/molecules

4. Physical Change Examples = Change in state or phase change Dissolving
Compressing
Light emission/absorption
Electrons passing through metals

5. Physical Change More Examples = boiling of a liquid melting of a solid
dissolving a solid in a liquid to give a homogeneous mixture
making a solution

6. Cl-1 Cl-1 2 Chemical Change 1 Chemical Li +1 Bonds are made / broken
Change in oxidation states Li +1
Cl-1
Cl-1

7. Examples of Chemical Change
Burning hydrogen (H2) in oxygen (O2) gives H2O.
Chemical change or chemical reaction — transformation of one or more atoms or molecules into one or more different molecules.

8. Sure Signs of a Chemical Change “Chemists Get Practice Trying Labs”
Color Change
Gas Produced (not from boiling!)
Precipitate – a solid formed by mixing two liquids together
Temperature Change
Light

9. Remember the Law of Conservation of Mass
In a physical change or a chemical reaction, mass is neither created or destroyed
(Antoine Lavoisier)

10. Matter, Classify Changes of Matter Let’s see if you can:
Characterize various changes of matter
Recognize that a change of state in matter is a physical change

11. Physical vs. Chemical Change
Examples:
melting
flame produced
paper cut
dissolving salt in water
tarnishes in air

12. Physical vs. Chemical Change
Examples:
rusting iron
mixing mud and water
burning a log
freezing water
grinding spices

13. A difference between physical change and chemical change is that
chemical change involves energy while physical change does not.
physical change involves energy while chemical change does not.
different kinds of molecules are present after a physical change but not after a chemical change.
different kinds of molecules are present after a chemical change but not after a physical change

14. In making a pizza, which process involves a chemical change?
Mixing spices for the sauce
Slicing pepperoni for the topping
Spreading cheese on the pizza
Baking the dough to form the crust

15. What’s the MATTER, Properties of Matter

16. Matter, Properties of Matter At the conclusion of our time together, you should be able to:
Explain the difference between the extensive and intensive properties and other types of properties
Distinguish between a physical property and chemical property

17. The Nature of Matter Gold Mercury
Chemists are interested in the nature of matter and how this is related to its atoms and molecules.

18. Chemistry & Matter
We can explore the MACROSCOPIC world — what we can see —
to understand the PARTICULATE worlds we cannot see.
We write SYMBOLS to describe these worlds.

19. A Chemist’s View Macroscopic 2 H2(g) + O2 (g) --> 2 H2O(g) Symbolic
Particulate

20. Properties of Matter 2 Types:
Extensive – depend on the amount of the sample
Always involves a number with unit
Examples = volume
mass
length

21. Properties of Matter (cont.)
Intensive – does not depend on the amount of the sample
Usually does not involve a number
Examples = density
melting, boiling point
malleability
ductility
color
odor

22. Properties
Every substance has a unique set of properties (characteristics that identify that substance)
Physical Properties-
Properties that can be measured without changing the identity and composition of the substance

23. Physical Property Examples-
Color
Odor
Density
Melting Point
Boiling Point
Hardness
Solubility

24. List Some Physical Properties of:
Graphite — this layer structure of carbon atoms reflects its physical properties.

25. Chemical Properties
Properties that describe the way a substance may change to form other substances
Only observed when a chemical reaction takes place

26. Chemical Property Examples
Combustible
Reactive with water or acid
Flammable
Corrosive
Decomposes in air

27. Physical vs. Chemical Properties
Physical Properties-
Properties that can be measured without changing the identity and composition of the substance
Chemical Properties-
Properties that can be measured by changing the identity and composition of the substance

28. Matter, Properties of Matter Let’s see if you can:
Explain the difference between the extensive and intensive properties and other types of properties
Distinguish between a physical property and chemical property

29. Properties of Matter 2 Types: Extensive –
depends on the amount of the sample
Intensive –
does not depend on the amount of the sample

30. Physical vs. Chemical Properties
Physical Properties-
Properties that can be measured without changing the identity and composition of the substance
Chemical Properties-
Properties that can be measured by changing the identity and composition of the substance

31. Physical vs. Chemical Property
Examples:
melts at 55oF
flammable
will tear easily
will dissolve in water
will tarnish

32. Physical vs. Chemical Properties
Examples:
will rust
mixture can be separated by boiling
burns
freezes at -20oC
can be crushed