12th Class Physics Atomic Physics Question Bank MCQs - Atoms

Taking the Bohr radius as \[{{a}_{0}}\] = 53 pm, the radius of \[{{\operatorname{Li}}^{++}}\]ion in its ground state, on the basis of Bohr's model, will be about

A) 53 pm.

B) 27 pm.

C) 18 pm.

D) 13 pm.

Correct Answer: C

Solution :

Option [c] is correct.

Explanation: According to Bohr's model of an atom, radius of an atom in its ground state is

\[r=\frac{{{r}_{0}}}{\operatorname{Z}}\]

where, \[{{r}_{0}}\] is Bohr's radius and Z is atomic number.

As given that,

\[{{r}_{0}}\] = 53 pm and atomic number of Lithium atom is 3

so, r=\[\frac{53}{3}\]=17.67 pm ≈18pm