Question

The Bohr orbit radius for the hydrogen atom $(n=1)$ is approximately $0.530\mathring{A}$ The radius for the first excited state $(n=2)$ will be:

• A. $0.13\mathring{A}$
• B. $1.06\mathring{A}$
• C. $4.77\mathring{A}$
• D. $2.12\mathring{A}$

Answer 1

The correct option is D $2.12\mathring{A}$

We know that the radius of Bohr orbit is given by

$r=0.530n^2{A}^o$

Where, $n=$ orbit number.

So, for orbit number 2 i.e. $n=2$

$r_2=0.530\times 4=2.12A^o$

Hence, the correct option is $D$