Please describe the structure of atom, with reference to the relative mass and charge.

At the centre of the atom, is the nucleus. This is made up of protons and neutrons. Protons are positively charged, with a relative charge of +1. Whilst neutrons are neutral (relative charge = 0).Surrounding the nucleus are electrons. These are arranged in energy levels and are negatively charged (relative charge = -1).Both protons and neutrons have a relative mass of 1. Whilst electrons are much lighter with a relative mass of 1/1840. The relative mass of electrons is so small, that it can be considered negligible.