Question

According to Bohr's theory radius of $n^{th}$ shell is given as $\frac{1}{r_n}\propto Z^y$ ($Z$ is atomic number). Here ${}^{\prime }{y}^{\prime }$ is:

• A. $-1$
• B. $1$
• C. $2$
• D. $-2$

Answer 1

Answer: (B)

$1$

According to Bohr's theory radius of any shell $r_n$ is proportional to $\frac{n^2}{Z}$ where n= principle quantum no and Z = atomic number.

So, $1/r_n$ is proportional to $\frac{Z}{n^2}$ .

So the correct option is B.