Question

The ionization energy of a hydrogen-like atom is 9 Rydberg. The radius of first orbit of this atom, as compared to the radius of first orbit of hydrogen atom, will be

• A. One-fourth
• B. Half
• C. One-third
• D. Three times

Answer 1

The correct option is C One-third

$I.E.=9R=R\times \frac{z^2}{nL}$
$z=3$
$\therefore =R_H\times \frac{H^2}{z}=\frac{R_H}{3}$