Question

which substance is a compound?
salt
phosphorus
sulfur
oxygen

Explanation:

A compound is a substance formed when two or more elements are chemically bonded together. Salt (sodium chloride, \(NaCl\)) is made of sodium (\(Na\)) and chlorine (\(Cl\)) elements. Phosphorus (\(P\)), sulfur (\(S\)), and oxygen (\(O_2\)) are elements (single - type atoms or molecules of the same atom), not compounds.

Answer:

salt