1. 2.4 States and Properties of Matter
General, Organic, and Biological Chemistry
Fourth Edition
Karen Timberlake
Chapter 2
Energy and Matter
2.4 States and Properties of Matter
Lectures
© 2013 Pearson Education, Inc.

2. Solids Solids have a definite shape. a definite volume.
particles that are close together in a rigid pattern.
particles that vibrate slowly in their fixed positions.
Amethyst, a solid, is a purple
form of quartz (SiO2).

3. Liquids Liquids have a definite volume, but not a definite shape.
the same shape as their container.
particles that are close together, but mobile.
particles that move slowly in random directions.

4. Gases Gases do not have a definite shape.
do not have a definite volume.
take the same shape and volume as their container.
have particles that are far apart.
are composed of fast moving particles that have little attraction to each other.

5. A Comparison of Solids, Liquids, and Gases

6. Learning Check Identify each as a (S) solid, (L) liquid, or (G) gas.
__ A. It has a definite volume, but takes the shape of
the container.
__ B. Its particles are moving very rapidly.
__ C. It fills the volume of a container.
__ D. It has particles in a fixed arrangement.
__ E. It has particles that are close together and are mobile.

7. Solution Identify each as a (S) solid, (L) liquid, or (G) gas.
__ A. It has a definite volume, but takes the shape of
the container.
__ B. Its particles are moving very rapidly.
__ C. It fills the volume of a container.
__ D. It has particles in a fixed arrangement.
__ E. It has particles that are close together and are mobile. L G G S L

8. Physical Properties Physical properties
are observed or measured without affecting the identity of a substance.
include shape, physical state, boiling and freezing points, density, and color of that substance.

9. Physical Properties of Copper

10. Physical Change A physical change occurs in a substance if there is
a change in the state.
a change in the physical shape.
no change in the identity and composition of the
substance.

11. Physical Change
Water is found in all three physical states, solid, liquid, and gas.
Water changes state from a solid to a liquid and from a liquid to a gas
as heat is added.
Q: Is heat added or released when liquid water freezes?

12. Change of State: Melting and Freezing
At the melting point, a solid is converted to a liquid.
At the freezing point, a liquid is converted to a solid.

13. Change of State: Evaporation and Condensation
At the boiling point, a liquid is converted to a gas.
At the same temperature, a gas is converted to a liquid as heat is removed.

14. Heating Curve
A heating curve represents changes in temperature and physical state as heat is added to a substance.
A horizontal line represents a phase change; a diagonal line represents an increase in the temperature of the substance.

15. Cooling Curve
A cooling curve represents changes in temperature and physical state as heat is removed from a substance.
A horizontal line represents a phase change; a diagonal line represents a decrease in the temperature of the substance.

16. Change of State: Sublimation and Deposition
Sublimation is the process that describes the physical change of a solid directly to a gas.
Deposition is the process that describes the physical change of a gas directly to a solid.

17. Examples of Physical Change

18. Chemical Properties and Chemical Change
Chemical properties describe the ability of a substance to change into a new substance.
During a chemical change a new substance forms that has
a new composition.
new chemical and physical properties.

19. Example of Chemical Change
Iron (Fe) nails react with oxygen (O2) to form rust (Fe2O3).
Iron Fe
Iron (III) oxide
Fe2O3

20. Examples of Chemical Change

21. Summary of Chemical and Physical Properties and Changes

22. Learning Check
Classify each of the following as a (1) physical change or (2) chemical change.
A. __ burning a candle
B. __ ice melting on the street
C. __ toasting a marshmallow
D. __ cutting a pizza
E. __ polishing a silver bowl

23. Solution
Classify each of the following as a (1) physical change or (2) chemical change.
A. __ burning a candle
B. __ ice melting on the street
C. __ toasting a marshmallow
D. __ cutting a pizza
E. __ polishing a silver bowl 2 1 2 1 2