Q. The radius of hydrogen atom is 0.53Å. The radius of $\ _{3}Li^{2 +}$ is of
A) 1.27 Å
B) 0.17 Å
C) 0.57 Å
D) 0.99 Å
Explanation
(b)
The radius of hydrogen atom=0.53Å
$\ _{3}Li^{2 +}$ion also has only one electron but it has 3 proton in nucleus, hence its electron feels three times more attraction from nucleus in comparison of hydrogen atom. Thus, the radius of $\ _{3}Li^{2 +}$will be
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = \frac{0.53}{3} = 0.17\ \mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.