Question

3. In photo electric effect, the work function of Li, Na and Rb are 2.41eV, 2.3eV and 2.09e1 respectively. The work function of the "K" could approximately be in eV​

Answer 1

Answer:

2.20 eV

Explanation:

As the size of the atom (element) increases, the energy required to overcome the attractive force on outermost electron decreases.

Li,Na,K and Rb are the members of the same group and have the following order of size:  

Li<Na<K<Rb

Thus, the energy in case of K is intermediate of Rb and Na, i.e.,

2.30 > K > 2.09 or the energy for K is 2.20 eV.