The radius of the second Bohr orbit for hydrogen atom is :
(Planck's constant, `h = 6.6262 xx 10^(-34) Js`, mass of electron = `9.1091 xx 10^(-31) kg`, charge of electron `e = 1.60210 xx 10^(-19) C`, permittivity of vaccum `in_0 = 8.854185 xx 10^(-12) kg^(-1) m^(-3) A^2)`

Options

A. `0.529 Å`
B. `2.12 Å`
C. `1.65 Å`
D. `4.76 Å`

Answer

B

Explanation

`r = a_(0) xx (n^(2))/(Z)` (`a_(0) =` Bohr radius)
`:. r = 0.529 xx (2^(2))/(1) = 0.529 xx 4 Å = 2.12 Å`