Question

The energy required to excite an electron from n = 2 to n = 3 energy state is 47.2eV. The charge number of the nucleus, around which the electron is revolving, will be –

• A. 25
• B. 10
• C. 15
• D. 20

Answer 1

Answer: (A)

25

Answer 2

1.9z² = 47.2 ̃ z² = $\frac{47.2}{1.9}$ = 25