This Study Mind Tutorial covers the following specification points:

Edexcel: 1.1-1.4

1.1 know the structure of an atom in terms of electrons, protons and neutrons

1.2 know the relative mass and relative charge of protons, neutrons and electrons

1.3 know what is meant by the terms ‘atomic (proton) number’ and ‘mass number’

1.4 be able to determine the number of each type of sub-atomic particle in an atom, molecule or ion from the atomic (proton) number and mass number