Q.

Considering Bohr's atomic model for hydrogen atom:

(A) the energy of H atom in ground state is same as energy of He+ ion in its first excited state.

(B) the energy of H atom in ground state is same as that for Li++ ion in its second excited state.

(C) the energy of H atom in its ground state is same as that of He+ ion for its ground state.

(D) the energy of He+ ion in its first excited state is same as that for Li++ ion in its ground state.

Choose the correct answer from the options given below:         [2025]

1 (B), (D) only  
2 (A), (B) only  
3 (A), (D) only  
4 (A), (C) only  

Ans.

(2)

E=13.6z2n2 eV

EHe+ 1st excited state = –13.6 eV

ELi2+ 2nd excited state = –13.6 eV

(A), (B) are correct.

EZn2

ZH=1  ZHe+=2  ZLi+2=3

1st excited state  n = 2

2nd excited state  n = 3

From the given statements only (A) and (B) are correct.