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Energy required for the electron excitation in Li++ from the first to the third Bohr orbit is:

1. 36.3 eV
2. 108.8 eV
3. 122.4 eV
4. 12.1 eV

Correct answer: 108.8 eV

Solution

For Li++ (Z=3): E = 13.6*Z^2*(1/1^2 - 1/3^2) = 13.6*9*(8/9) = 108.8 eV.

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