Question

Which best describes a compound such as magnesium oxide

A. an impure substance that is made up of two elements
B. a mixture of two uncommon substances
C. a mixture of two common elements
D. a pure substance that is made up of different elements

Answer 1

D. a pure substance that is made up of different elements

Explanation:

There are two types of pure substances: elements and compounds.

Elements are made up of only one type of atom. And compounds are pure substances, that are made up of more than one type of element. Like - magnesium oxide. It is a compound of a metal with a non-metal and is held together with ionic bonds.