Choose the correct alternative from the clues given at the end of the each statement:

(a) The size of the atom in Thomson’s model is .......... the atomic size in Rutherford’s model. (much greater than/no different from/much less than.)


(b) In the ground state of .......... electrons are in stable equilibrium, while in .......... electrons always experience a net force. (Thomson’s model/ Rutherford’s model.)


(c) A classical atom based on .......... is doomed to collapse. (Thomson’s model/ Rutherford’s model.)


(d) An atom has a nearly continuous mass distribution in a .......... but has a highly non-uniform mass distribution in .......... (Thomson’s model/ Rutherford’s model.)


(e) The positively charged part of the atom possesses most of the mass in .......... (Rutherford’s model/both the models.)

(a) The correct alternative is: no different from


Explanation: The size of the atom in the thomson’s model and the size of the atom in Rutherford’s model of an atom were of same magnitude.


(b) The correct alternative is: Thomson’s model, Rutherford’s model


Explanation: This is because when the electrons are in the ground state in case of Thomson’s model, they are in stable equilibrium whereas in case of Rutherford’s model of an atom, when electrons are at ground state, they experience a net force.


(c) The correct alternative is: Rutherford’s model


Explanation: A classical atom based on Rutherford’s model is doomed to collapse.


(d) The correct alternative is: Thomson’s model, Rutherford’s model


Explanation: The mass distribution of an atom is nearly continous in case of Thomson’s model of an atom, whereas in case of Rutherford’s model of an atom, the mass distribution is not uniform or continuous.


(e) The correct alternative is: both the models.


Explanation: In both Rutherford and Thomson’s model of an atom, the most of the mass is due to the positive part of the atom i.e. protons.


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