Question

The radius of hydrogen atom in its ground state is 5.3 × 10^–11 m. After collision with an electron it is found to have a radius of 21.2 × 10^–11 m. What is the principal quantum number n of the final state of the atom ?

• A. n = 4
• B. n = 2
• C. n = 16
• D. n = 3

Answer 1

Answer: (B)

n = 2

Answer 2

r µ n²

$\frac{5.3 \times 10^{–11}}{21.2 \times 10^{–11}}$ = $\frac{1}{n^{2}}$

n² = 4 , n = 2