Question

65. )The energy of an electron in the first Bohr
orbit of H atom is –13.6V. The possible
energy value(s) of the excited state(s) for
electrons in Bohr orbits of hydrogen is/are
(A) -3.4eV
(B) 4.2 eV
(C) 6.8V
(D) +6.8eV(1998
​

Answer 1

Converting J/mol to electron Volt, we have E=-13.6 eV

Now,

En=−2π2me4Z2n2h2(4πϵ0)2

(symbols with usual meanings).

For hydrogen, Z=1, so En=−13.6n2

Hence E1=-13.6 eV, E2=-3.4 eV

Excitation energy to move to 2nd orbit= E2−E1=−3.4−(−13.6)=10.2 eV=9.84×105 J/mol