Answer:
[tex]\mathbf{E_1 = -40.8 \ eV}[/tex]
[tex]\mathbf{E_2= -10.2 \ eV}[/tex]
[tex]\mathbf{E_3=-4.533 \e V}[/tex]
Explanation:
In an hydrogen like atoms, the formula related to the energy of an nth quantum number is:
[tex]E_n =\dfrac{ -13.6 \times Z}{n^2}[/tex]
where;
lithium Z = 3
therefore, the energy levels for Li²⁺ are
n=1 , n=2, n= 3
[tex]E_1 =\dfrac{ -13.6 \times 3}{1^2}[/tex]
[tex]E_1 = -13.6 \times 3[/tex]
[tex]\mathbf{E_1 = -40.8 \ eV}[/tex]
[tex]E_2=\dfrac{ -13.6 \times 3}{2^2}[/tex]
[tex]E_2=\dfrac{ -13.6 \times 3}{4}[/tex]
[tex]\mathbf{E_2= -10.2 \ eV}[/tex]
[tex]E_3=\dfrac{ -13.6 \times 3}{3^2}[/tex]
[tex]E_3=\dfrac{ -13.6 \times 3}{9}[/tex]
[tex]\mathbf{E_3=-4.533 \e V}[/tex]