Chemistry - Atomic Structure Question with Solution | TestHub
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :
Assertion A: In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface.
Reason R : When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place.
In the light of the above statements, choose the most appropriate answer from the options given below :
Options:
Answer:
Solution:
The threshold frequency is the minimum frequency required for emission of electrons from the outermost shell. The light with frequencies lower than threshold would not eject photoelectrons from the shell of an atom. As for the emission kinetic energy of an electron should be greater than or equal to zero. Hence, the photoelectric emission will take place only when the energy of a photon is greater than the energy possessed by the electron. Atoms are ionised resulting in transfer of energy when photons of sufficient energy strike the metal surface.