Question

What is the energy associated with first orbit of Li²⁺ (R_H = 2.18 × 10^-18)?

Options

• - 8.72 × 10^-18 J

• - 34.88 × 10^-18 J

• - 218 × 10^-18 J

• - 19.62 × 10^-18 J

Answer 1

- 19.62 × 10^-18 J

Explanation:

The formula of energy associated with a hydrogen atom is given by

`"E"_"n" = - 2.18 xx 10^-8 "Z"^2/"n"^2`J

For Li²⁺, Z = 3, n = 1 

`"E"_"n" = - 2.18 xx 10^-8 xx (3)^2/(1)^2 = - 2.18 xx 10^-8 xx 9/1`

= - 19.62 × 10^-18 J