Back to basics with today’s graphic, with a look at the different ways compounds in organic chemistry can be represented. Obviously, if you’re a chemist, these will all be second nature, but as was ...

For example, magnesium oxide is made up of two elements, magnesium and oxygen. Its formula is MgO. This shows that it has one atom of magnesium for every one atom of oxygen.

There are lots of different substances but only just over a hundred elements. An element is a substance that is made up of only one kind of atom. The atoms in a particular element are the same as each ...