Q.

Which of the following statements regarding the energy of the stationary state is true in the following one-electron systems           [2026]

1 -1.09×10-18 J for second orbit of H atom.  
2 -2.18×10-18 J for third orbit of Li2+ ion.  
3 +8.72×10-18 J for first orbit of He+ ion.  
4 +2.18×10-18 J for second orbit of He+ ion.  

Ans.

(2)

En=-2.18×10-18Z2n2 J/atom

For 3rd orbit of Li2+ ion

=-2.18×10-18×3232=-2.18×10-18 J.