Question

In the hydrogen atom, the energy difference between the states n=2 and n=3 is E eV. The ionisation potential of H atom is:

• A. 3.2 E
• B. 5.6 E
• C. 7.2 E
• D. 13.2 E

Answer 1

Answer: (C)

7.2 E

Energy difference= $E=E_o[\frac{1}{(2{)}^2}-\frac{1}{(3{)}^2}]=\frac{5E_o}{36}$

$\Rightarrow E_o=7.2E$

Ionization potential=$E^1=E_o[\frac{1}{(1{)}^2}-\frac{1}{\infty }]=E_o$

$\therefore E^{\prime }=7.2E$