Question

The radius of hydrogen atom in the ground state is 5.3 × 10^–11m. When struck by an electron, its radius is found to be

21.2 × 10^–11 m. The principal quantum number of the final state will be –

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (B)

2

Answer 2

r = a₀$\frac{n^{2}}{Z}$ = a₀, 4a₀, 9a₀,…. = 0.53Å, 2.12Å,……

̃ n = 2 for r = 2.12Åss