C2 3.1 The structure and mass of atoms

The structure of atoms:                                                                                                                

Atoms are made of three smaller subatomic particles called, protons, neutrons and electrons.

Proton: charge= +1: mass=1

Neutron: charge= 0 (neutral): mass=1

Electron: charge= -1: mass= nearly 0.

At the centre of an atom is a tiny nucleus, the protons and neutrons are in here, so this is were most of the mass is. The electronsmove around the nucleus occupying energy levels.

Atomic mass:

Different atoms have different masses because they…