Structure of the Atom Class 9 Extra Questions

CBSE Notes for Structure of the Atom Class 9 Extra Questions

Atomic Models Everything around us is made up of tiny particles called atoms. There are three subatomic particles namely electron, proton, and neutron. Electron (e–1) was discovered by J.J. Thomson. It carries one unit of negative charge. Proton (p+) was discovered by Goldstein. It carries one unit of a positive charge. Neutron (n0) was discovered by J. Chadwick. It is a neutral atomic particle. To describe the arrangement of subatomic particles within the atom, many models of an atom are proposed. Some of them are Thomson’s Model, Rutherford’s Model, Bohr’s Model. Thomson’s Model is also known as the w watermelon or the plum pudding model as the electrons in the sphere of the positive charge were just like dry fruits in a spherical Christmas pudding. Rutherford’s alpha-particle scattering experiment led to the discovery of the nucleus of an atom. Rutherford’s model of the atom proposed that a very tiny nucleus is present inside the atom and electrons revolve around this nucleus. Please refer Structure of the Atom Class 9 Extra Questions for more information.