Which substance is a compound?

water

O gold

oxygen

O hydrogen

A compound is a chemical combination of two or more elements ... water is made up of Hydrogen and oxygen hence the answer is water

Water

Explanation:

This is actually a chemistry question but I'll answer it anyways

The definition of a chemical compound is " a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds. "

Compounds are homogenous, which means that they are evenly distributed and have 2 or more different elements from the definition

Therefore the answer is that water is a compound as its chemical make up is H2O.

Gold is made up of 1 element

Oxygen is made up of 1 element,

Hydrogen is made up of 1 element

Therefore these options are not viable since they do not contain 2 or more elements.