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Question
An electron is orbiting in 5th Bohr orbit. Calculate ionisation energy for this atom, if the ground state energy is -13.6 eV.
Solution
Ground state energy E1 = −13.6 eV
E5 = ?
Energy of electron in Bohr’s orbit is inversely proportional to the square of the principal quantum number.
`therefore"E"_5/"E"_1="n"_1^2/"n"_5^2`
`therefore"E"_5/"E"_1=1^2/5^2`
`therefore"E"_5=(-13.6)/25=-0.544"eV"`
The ionization energy = E∞ - E5 = 0 − (−0.544) = 0.544 eV
Hence, the ionization energy in the 5th orbit is 0.544 eV.
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