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.

An element's atomic number defines it. An element with 17 protons will always be chlorine. However an element's mass numbers can vary, which means that it can have different numbers of neutrons. So ...

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 ...

Mrs Roberts: What do you think you're made of? Mr Spellman: Big question. Grit, determination, hard-working, handsome, charming, funny. Mrs Roberts: Well, I guess. But you're actually made of atoms.

This article was updated June 28 at 4:54 p.m. ET. Scientists have long wondered whether there is a limit to the number of protons and neutrons that can be clustered together to form the nucleus of an ...

HEISENBERG has discussed the hypothesis that the nucleus of an atom is composed of neutrons and protons only, the neutron being regarded as a fundamental entity and not as a combination of an electron ...

Individual protons and neutrons in atomic nuclei turn out not to behave according to the predictions made by existing theoretical models. This surprising conclusion, reached by an international team ...

The stuff of daily existence is made of atoms, and all those atoms are made of the same three things: electrons, protons and neutrons. Protons and neutrons are very similar particles in most respects.