Asubstance with a definite shape and volume is a of matter.

solid

Explanation:

Solid  involves the state in which matter has a definite shape and volume. In that respect, solids can be crystalline, which means that the atoms or molecules are arranged in a repeating pattern of rows, like iron, diamond and ice. Solids can also be amaorphous, which are constituted by atoms or molecules in no organized pattern, such as rubber and wax.

if you mean hydrogen and oxygen then water is the product