Question

The velocity of an electron in the second orbit of sodium atom (atomic number = 11) is v. The velocity of an electron in its fifth orbit will be.

• A. v
• B. $\frac{22}{5}v$
• C. $\frac{5}{2}v$
• D. $\frac{2}{5}v$

Answer 1

Answer: (D)

$\frac{2}{5}v$

Answer 2

v_n $\propto \frac{1}{n}$ ⇒ $\frac{v_{5}}{v_{2}} = \frac{2}{5} \Rightarrow v_{5} = \frac{2}{5}v_{2} = \frac{2}{5}v$.