18/04/2026
Inside The Atom.
An atom has a small central nucleus that contains protons and neutrons. Protons have a positive charge, neutrons have no charge, and together they make up most of the atom’s mass. Surrounding the nucleus are electrons, which have a negative charge and are arranged in shells. These electron shells help explain how atoms behave, bond, and take part in chemical reactions. Understanding atomic structure gives us a strong foundation for learning the rest of Chemistry.