Question

The Bohr orbit radius for the hydrogen atom $(n=1)$ is approximately $0.530\,�$. The radius for the first excited state $(n=2)$ orbit is (in $�$ )

• A. 0.13
• B. 1.06
• C. 4.77
• D. 2.12

Answer 1

Answer: (D)

2.12

Answer 2

Radius of hydrogen atom $=0.530\,�$,
Number of excited state $(n)=2$ and atomic number of hydrogen atom $(Z)=1$.
We know that the Bohr radius.
$(r)=\frac{n^{2}}{Z} \times=\frac{(2)^{2}}{1} \times 0.530$
$=4 \times 0.530=2.12\,�$