In photoelectric effect, if the energy required to overcome the attractive forces on the electron (work functions) of Li, Na and Rb are 2.41 eV, 2.30 eV and 2.09 eV respectively, the work function of ‘K’ could approximately be in eV

Options

A. 2.52
B. 2.2
C. 2.35
D. 2.01

Answer

(b)

Explanation

`Atomic size alpha 1/ Work function`
The order of atomic size of given elements is Rb> K>Na > Li
`:.`Energy in case of K is lesser than Na and higher thanRb i.e, Na > K > Rb 2.30 > K> 2.09
`:.`The correct answer is 2.20 eV