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 ...

Part of Physics (Single Science) Unit 1: Atomic and nuclear physics Most of the mass and all of the positive charge of an atom is in the nucleus. Most of an atom is empty space, (a vacuum). In 1897, ...