Everything we can see and touch, and quite a lot that we can’t as well, is made of tiny particles called atoms. Some substances, like particles of this iron, contain only one kind of atom. Iron is an ...

Atoms are made up of a nucleus, protons and electrons. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Atoms are the basic units of matter.

The periodic table is one of the triumphs of science. Even before certain elements had been discovered, this chart could successfully predict their masses, densities, how they would link up with other ...