Question

The velocity of an electron in the third orbit of hydrogen atom?

• A. $7.28\times {10}^{7}cm{sec}^{-1}$
• B. $6.5\times {10}^{8}cm{sec}^{-1}$
• C. $7.38\times {10}^{9}cm{sec}^{-1}$
• D. $3.12\times {10}^{6}cm{sec}^{-1}$

Answer 1

Answer: (B)

$6.5\times {10}^{8}cm{sec}^{-1}$

We know $v=v_{0}z/n$ where $v_0=2.165\times {10}^{8}cm$

So for third orbit and hydrogen atom n is 3 and z = 1

$v=2.165\times {10}^8\times 3=6.5\times {10}^{8}cmse{c}^{-1}$