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  4. Energy of electron in first orbit in H2 atom is -13.6 ev, its energy in fourth orbit is

Q. Energy of electron in first orbit in $H_2$ atom is $-13.6\,ev$, its energy in fourth orbit is

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Solution:

$E _{ n }=- E _{1} / n ^{2}=-13.6 / 4^{2}=-0.85\, eV$

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