Q 12-12-008NEETNEET 2023Top questionEasy
The radius of inner most orbit of hydrogen atom is $5.3 \times 10^{-11}$ m. What is the radius of third allowed orbit of hydrogen atom?
Answer: (D) $4.77$ Å
Concept. In hydrogen the Bohr radius grows as $r_n = n^2 r_1$.
Step 1. Substitute. $r_1 = 5.3 \times 10^{-11}$ m $= 0.53$ Å:
$$r_3 = 9 \times 0.53 = 4.77\ \text{Å}$$
Answer. $4.77$ Å (Option D).
Solution by Sreeraj P, M.Sc Physics