Q. The one electron species having ionisation energy of 54.4 eV is
A) H
B) $He^{+}$
C) $B^{4 +}$
D) $Li^{2 +}$
Explanation
(b)
Out of other alternates, $He^{+}$has ionisation energy of 54.4 eV because in $He^{+}$effective nuclear charge is fairly high and ionic size is small.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.