The smallest particle of an atom is the subatomic particle called the electron. Electrons have a negative charge and are located outside the atomic nucleus in specific energy levels or orbitals. They are considered to be elementary particles, meaning they are not composed of smaller particles.
An atom consists of a central nucleus, which contains protons and neutrons, and electrons that orbit around the nucleus. Protons have a positive charge, while neutrons are electrically neutral. The number of protons determines the atomic number of an atom, defining its elemental identity.
The electron's mass is significantly smaller compared to protons and neutrons. In fact, the mass of an electron is approximately 1/1836 times the mass of a proton. However, despite its small mass, the electron plays a crucial role in determining the chemical properties and behavior of atoms, as it is involved in chemical bonding and the formation of chemical compounds.