Ch. 2: “Matter” Section 2.3 Review: “Properties of Matter”
a. is shiny & silver physical b. melts easily physical c. burns in air chemical d. has a density of 2.3 g/cm3 physical e. tarnishes in moist air chemical 1. Classify the following as either chemical or physical properties:
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.
a. ice melting in a drink physical b. sugar added to lemonade physical c. mixing vinegar & baking soda to generate bubbles chemical d. plants using CO2& H2O to form O2& sugar chemical 3. Classify the following as either a chemical or physical change:
4. Explain why changes of state are physical changes. • The composition of the substance does not change when it changes state.
5. Categorize the following as either absorbing or releasing energy. a. solid CO2going toCO2gas • absorbed b. rubbing alcohol evaporating • absorbed c. aluminum solidifying in a mold • released d. chocolate melting • absorbed
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
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.