Which substance is a compound?
salt
phosphorus
sulfur
oxygen

The correct answer is salt.

A compound is a chemical substance which is formed by the combination of two or more elements, joined together in a fixed proportion.

Salt is a chemical compound which is formed by the reaction of an acid with a base. For example- NaCl ( sodium chloride) is a common salt. It is formed by the combination of two elements. Therefore, salt is a compound.

On the contrary, Phosphorous (P), sulfur (S) and Oxygen (O₂) are composed of a single element. Therefore, they are not compounds.

Thus, the correct answer for the compound is Salt .

plato users:

d.  

there was a variety of food available on island x, but there were only large seeds and nuts on island y.

answercells,tissues,organs,organ,system-organism;

levels of biological organization; organism,population,community,ecosystem,biome,biosphere,

hope this .good luck