`IE "for" He^+ "is" 1.96 xx 10^-19 J "atom"^-1`. Calculate the energy of first stationary state of `Be^(+3)`.

Options

A. `6.84 xx 10^-19 J "atom"^-1`
B. `6.84 xx 10^-23 J "atom"^-1`
C. `7.84 xx 1019 J "atom"^-1`
D. `7.84 xx 1023 J "atom"^-1`

Answer

A

Explanation

For `He^+, E_1 = E_1 "fo"r H xx Z^2 = E_1 xx 4`
For `Be^(3+), E_1 = E_1 "for" H xx Z^2 = E_1 xx 16`
For `Be^(+3), E_1 = E_1 "for" He^+ xx (16)/(4)`
=`1.96 xx 10^-19 xx 4`
=`7.84 xx 10^-19 J//"atom"`.