Atom

Definition

An atom is the smallest unit of a chemical element that retains its unique properties. It consists of a nucleus containing protons and neutrons, surrounded by electrons in orbitals.

Related terms

Element:

A substance that cannot be broken down into simpler substances by chemical means, composed of atoms with the same number of protons.

Proton:

A subatomic particle found in the nucleus of an atom, carrying a positive electric charge.

Electron: A subatomic particle with a negative charge, orbiting the nucleus of an atom in various energy levels or orbitals