Question

What is the energy of an electron in stationary state corresponding to n = 2?

Options

• - 3.45 × 10^-18 J

• - 0.545 × 10^-18 J

• 0.545 × 10^-18 J

• 3.45 × 10^-18 J

Answer 1

- 0.545 × 10^-18 J

Explanation:

Energy of an electron is given by

`"E"_"n" = (- 13.6)/"n"^2` eV

For n = 2

E = `(- 13.6)/(2 xx 2)`eV = `(- 13.6)/4`eV   ...[1 eV = 1.602 × 10^-19 J]

`= - 3.4 xx 1.602 xx 10^-19` J

`= - 5.45 xx 10^-19` J

or = - 0.545 × 10^-18 J