Priyam Study Centre

A Page about Chemistry and Related Topics.

Jul 16, 2018

Thompson’s Model


Newton had long back shown that sunlight could be separated by passage through a prism, the light of many colors (red to violet), thus giving rise to a spectrum. A light pattern consisting of a continuous sequence of colors varying from red to violet, is called continuous spectrum. On other hand some light source may give rise to one or few colors lines separated by dark spaces. This type of spectrum is called line spectrum.

 Plank Theory: 

Plank postulated a new and revolutionary that, radiant energy emitted by an electron was not continuous in nature, but rather was emitted in discrete unit, bundles or quanta. He assumed that energy of matter was bundles. A bundles of energy that is the quantum of energy emitted by light is called photon.

Thompson’s Model: 

Thompson’s proposed that the shape of an atom is resembles that of a sphere having the radius of the order of the order〖10〗^(-10) m. The positively charged particles are uniformly distributed with Charge electrons arranged in such a manner that the atom is electrostatic ally stable. Thomson’s Model also called Plum Pudding Model or Watermelon Model. The mass of a atom is uniformly distributed all over the atom

Limitation of Thomson’s Model: 

1. Thompson’s atomic model explained the overall neutrality of an atom. Its assumption that mass of an atom is uniformly distributed all over the atom was inconsistent with the same of scattering alpha particle reveled that most of space in an atom is empty contradicted Thompson’s atomic model. 2. There is no experimental evidence regarding this model.