37.Classify each substance as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous. a. sweat b. carbon dioxide c. aluminum d. vegetable soup

40.Complete the table.

41.Determine whether each molecular diagram represents a pure substance or a mixture. If it represents a pure substance, classify the substance as an element or a compound. If it represents a mixture, classify the mixture as homogeneous or heterogeneous. a. c.

b. d.

45. Classify each property as physical or chemical. a. the tendency of ethyl alcohol to burn b. the shine on silver c. the odor of paint thinner d. the flammability of propane gas