KCET2020PhysicsAtomic Physics
A beam of fast moving alpha particles were directed towards a thin film of gold. The parts A, B and C of the transmitted and reflected beams corresponding to the incident parts A, B and C of the beam are shown in the adjoining diagram. The number of alpha particles in
Options
- AB^ will be minimum and in C^ maximum
- BA^ will be maximum and in B^ minimum
- CA^ will be minimum and in B^ maximum
- DC^ will be minimum and in B^ maximum
Correct answer
B. A^ will be maximum and in B^ minimum
Step-by-step solution
According to Rutherford's -particles scattering experiment, following observations are made (i) Most of the -particles passed through the gold foil undeflected. (ii) Only about 0.14 % of the incident -particles scattered by an angle greater than 1^ . (iii) About one -particle in every 8000 -particles deflects by angle more than 90^ . So, from above observation, we can conclude about the number of -particle in given figure as, n_ A^ >n_ C^ >n_ B^ i.e., number of -particle will be maximum in A^ and minimum in B^ .