Question

The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?

• A. He⁺ (n=2)
• B. Li²⁺ (n=2)
• C. Li²⁺ (n=3)
• D. Be³⁺ (n=2)

Answer 1

The correct option is D

Be³⁺ (n=2)

$r_n$= $0.529$ $\frac{n^2}{Z}$$A^{\circ }$

For hydrogen,$n=1$ and $Z=1$;

Therefore $r_H$ = $0.592$

For $B{e}^{3+}$,$n$=$2$ and $Z$=$4$;

Therefore $B{e}_{3+}$=$\frac{0.529\times 2^2}{4}$