Question

The radius of the second Bohr orbit for the hydrogen atom is :

(Planck’s constant, h = 6.262×10^-34Js: Mass of electron = 9.1091×10^-31kg; Charge of electron e = 1.60210×10^-19C; permittivity of vacuum ε₀ = 8.854185×10^-12kg^-1m^-3A²)

(1) 1.65 A

(2) 4.76 A

(3) 0.529 A

(4) 2.12 A

Answer 1

(4) 2.12 A 

Radius of n^th Bohr orbit in H atom = 0.53 n²/Z

For hydrogen Z = 1

Radius of 2^nd Bohr orbit in H atom = 0.53 ×2²/1 = 2.12