Many of the items you purchase are mixtures of pure compounds. Select three of these commercial products and prepare a list of the ingredients that are pure compounds.

Compounds and elements are a. always solids. b. mixtures. c. pure substances. d. dense.

What properties distinguish solids from liquids? Liquids from gases? Solids from gases?

The amount of heat required to melt 2 lbs of ice is twice the amount of heat required to melt 1 lb of ice. Is this observation a macroscopic or microscopic description of chemical behavior? Explain your answer.

What is the difference between an element and a compound?

How does an element differ from a compound? How are they similar?

How does an atom differ from a molecule? In what ways are they similar?

How does a heterogeneous mixture differ from a homogeneous mixture? How are they similar?

How does a homogeneous mixture differ from a pure substance? How are they similar?

Explain the difference between a molecular element and a molecular compound.

How are the molecules in oxygen gas, the molecules in hydrogen gas, and water molecules similar? How do

How are the molecules in oxygen gas, the molecules in hydrogen gas, and water molecules similar? How do they differ?

How does a heterogeneous mixture differ from a homogeneous mixture? How are they similar?

Identify each of the following statements as being most similar to a hypothesis, a law, or a theory. Explain your reasoning. (a) The pressure of a sample of gas is directly proportional to the temperature of the gas. (b) Matter consists of tiny particles that can combine in specific ratios to form substances with specific properties. (c) At a higher temperature, solids (such as salt or sugar) will dissolve better in water.