Class 9 Chemistry Structure of The Atom Structure of Atom

Structure of Atom

  • Atoms are made up three of subatomic particles: electrons, protons and neutrons.
  • Electrons have negative charge, protons have positive charge and neutrons are neutral (no charge) in nature.
  • Protons and neutrons are present in small nucleus at the centre of the atom.
  • Whole of mass of atom is concentrated in the nucleus while the electrons, which are outside the nucleus, have very, very, small mass.
  • Electrons are found outside the nucleus. The electrons move around the nucleus in fixed circular orbits called energy levels or shells.


  • The atoms of different elements differ in the number of protons, electrons and neutrons.
  • Note: - Hydrogen atom is made up of only one electron and one proton.


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