Question

Which hydrogen like species will have same radius as that of Bohr orbit of hydrogen atom?

• A. $n=2, Li^{2+}$
• B. $n=2, Be^{3+}$
• C. $n=2, He^+$
• D. $n=3, Li^{2+}$

Answer 1

Answer: (B)

Expression for Bohr's orbit is, $r_{n}=\frac{a_{0} n^{2}}{Z}=a_{0}$
when $n=2, Z=4$.