Q.

Assuming the validity of Bohr's atomic model for hydrogen like ions the radius of Li++ ion in its ground state is given by 1Xa0, where X =. (Where a0 is the first Bohr's radius.)          [2025]

1 2  
2 1  
3 3  
4 9  

Ans.

(3)

r=a0n2Z and Z=3 for Li+2 and n=1

  r=a0123=a03

  X=3