What is the difference between an element and a compound?

1 Answer
Oct 14, 2016

An element is made up of atoms that are all the same.


An example is hydrogen, where all molecules are made up of two hydrogen atoms: #H_2#

Compounds are made up out of different types of atoms:
Water #H_2O#, where every molecule is made up out of two hydrogen and one oxygen atom.

If all molecules in a substance are the same, we speak of a pure substance, otherwise it's a mixture.