Answer:
n=3
Explanation:
The expression for the energy of an electron for the hydrogen atom in the nth orbit is:-
[tex]E_n=-2.18\times 10^{-18}\times \frac{1}{n^2}\ Joules[/tex]
Given that:-
[tex]E_n=-2.42\times 10^{-19}\ Joules[/tex]
Applying in the equation to find the value of n as:-
[tex]-2.42\times 10^{-19}=-2.18\times 10^{-18}\times \frac{1}{n^2}[/tex]
[tex]n^2=\frac{2.18\times 10^{-18}}{2.42\times 10^{-19}}[/tex]
[tex]n=\sqrt{\frac{21.8}{2.42}}=3[/tex]