1. Section 2.3 Review: “Properties of Matter”
Ch. 2: “Matter”
Section 2.3 Review: “Properties of Matter”

2. 1. Classify the following as either chemical or physical properties:
a. is shiny & silver
physical
b. melts easily
c. burns in air
chemical
d. has a density of 2.3 g/cm3
physical
e. tarnishes in moist air
chemical

3. 2. Describe several uses for plastic, & explain why plastic is a good choice for these purposes.
Strong, rigid plastic can be used in cases for electronic devices, such as CD players.
Flexible, transparent plastic can be used as food wrap.

4. 3. Classify the following as either a chemical or physical change:
a. ice melting in a drink
physical
b. sugar added to lemonade
c. mixing vinegar & baking soda to generate bubbles
chemical
d. plants using CO2 & H2O to form O2 & sugar

5. 4. Explain why changes of state are physical changes.
The composition of the substance does not change when it changes state.

6. 5. Categorize the following as either absorbing or releasing energy.
a. solid CO2 going to CO2 gas
absorbed
b. rubbing alcohol evaporating
c. aluminum solidifying in a mold
released
d. chocolate melting

7. 6. Calculate the density of a rock that has a mass of 454 g & a volume of exactly 100 cm3.
D = m/V
D = 454 g/100 cm3
D = 4.54 g/cm3

8. 7. Critical Thinking
Q: You need to build a raft. Write a paragraph describing the physical & chemical properties of the raft that would be important to ensure your safety. You are not limited to the properties discussed in this chapter.
A: Physical properties could include a density less than water, enough strength to not bend or break when a load is placed on it, & insolubility in water. Chemical properties could include not reacting with water or not burning.