AP EAMCET2012ChemistryClassification of Elements and Periodicity in Properties
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
- A2.52
- B2.20
- C2.35
- D2.01
Correct answer
B. 2.20
Step-by-step solution
As the size of atom (element) increases, energy required to overcome the attractive force on outermost electron decreases. Li , Na , K and Rb are the members of same group and have the following order of size Li 2.09 or the energy for K is 2.20 eV .