Question

49. Assuming Bohr's model for Li** atom, the first
excitation energy of ground state of Li** atom is
(1) 10.2 eV
(2) 91.8 eV
(3) 13.6 eV
(4) 3.4 eV

Answer 1

Assuming Bohr's model for Li** atom, the first excitation energy of ground state of Li** atom is equal to 91.8 eV.

• The first excitation energy of the ground state of a Li** atom signifies the transition form n=1 to n=2.
• The energy of the nth orbit of Li** atom is equal to -13.6*z²/n², where z = 9.
• The energy for n=1 and n=2 are -122.4 eV and -30.6 eV respectively.
• The excitation energy is equal to -30.6-(-122.4) = 91.8 eV.