JEE Main2014ChemistryStructure of AtomActual
The energy of an electron in first Bohr's orbit of H atom is − 13.6 eV . The energy value of electron in the first excited state of Li 2+ is :
Options
- A27.2   eV
- B− 30.6 eV
- C30.6   eV
- D− 27.2   eV
Correct answer
B. − 30.6 eV
Step-by-step solution
For H atom & H like species The electronic energy in the nth orbit is E n = - 13.6 z 2 n 2 eV E n Li 2 + = - 13.6 × 9 n 2 eV = - 122.4 eV n 2 If n = 2 E 2 Li 2 + = - 122.4 2 2 = - 30.6 eV