Question

Thomson's Atomic Model​

Answer 1

★ Thomson model of atom:-

→ According to this model:-

★ An atom posses a spherical shape (radius = 10-10m) in which the positive charge is uniformly distributed.

★ Electrons are embedded into it to balance the electrostatic forces. It gives the most stable electrostatic arrangement.

★ This model can be visualized as a pudding or watermelon of positive charge with plums or seeds (electrons) embedded into it. So this model is also named as plum pudding or raisin pudding or watermelon model.

★ Demerit of Thomson model of atom:-

→ It could not explain the experimental results of Rutherford's alpha-particle scattering.

★ Important feature of Thomson model of an atom:-

→ "The mass of the atom is assumed to be uniformly distributed over the atom".

Answer 2

J. J. Thomson proposed the first atom model, which is known as the plum pudding or raisin pudding or watermelon model. According to this model, an atom has a spherical shape in which the positive charge is uniformly distributed. The electrons are distributed in it, just like the seeds are distributed in a water melon or plums are distributed in a pudding. An important feature of this model is that the mass of the atom is assumed to be uniformly distributed over the atom. Also the total positive charge in an atom is equal to the total negative charge and hence the atom is electrically neutral.