Protons are tiny particles just a femtometer across, but without them, atoms wouldn't exist. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Part of Physics (Single Science) Unit 1: Atomic and nuclear physics Protons and neutrons are the heaviest particles in an atom and as a result they make up most of its mass. The mass of electrons is ...

Atoms are the fundamental components of matter, made up of three subatomic particles: protons, neutrons, and electrons. The structure of atoms determines the properties and behavior of different ...

Large atomic nuclei, containing many protons and neutrons, tend to be unstable. But stable nuclei do exist, and can be seen as an 'island of stability' on a graph of proton number against neutron ...