Question: 1) A substance is classified as either an element or a…

Answer: Compound

Question: 2) A sample of unknown composition was tested in a laboratory. The sample could not be decomposed by physical or chemical means. On the basis of these results, the laboratory reported that the unknown sample was most likely….

Answer: an element

Question: 3) The list below shows four samples: A,B,C, and D.

Which samples are mixtures?

Answer: A and B

Question: 4) The formula Al2S3 represents…

Answer: a compound

Question: 5) Which pair are classified as chemical substances?

Answer: compounds and elements