Calculate the Orbital Bohr Radius of The $n = 2$ Excited State in a Hydrogen Atom

Multiple Choice

Calculate the orbital Bohr radius of the $n = 2$ excited state in a hydrogen atom. $\left( r _ { 1 } = 0.0529 \mathrm {~nm} \right)$

A) $0.212 \mathrm {~nm}$
B) $0.170 \mathrm {~nm}$
C) $0.106 \mathrm {~nm}$
D) $0.244 \mathrm {~nm}$