The radius of the innermost electron orbit of a hydrogen atom is $5.3 × 10^{-11}m$. The radius of the third orbit is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $4.77 × 10^{-10} m$
$r_n$, Radius of an electron orbit, in hydrogen orbit in a hydrogen atom is -
$r_n=n^2r_0$
where,
n = principle quantum number of the orbit = 3
$r_0$ = Radius of 1st orbit = $5.3×10^{-11}m$
$∴r_3=(3)^2×5.3×10^{-11}$
$=4.77×10^{-10}$