Question

The orbital velocity of an electron in the ground state is $v$. If the electron is excited to energy state $-0.54eV$, its velocity will be

• A. $v$
• B. $\frac{v}{3}$
• C. $\frac{v}{5}$
• D. $\frac{v}{7}$

Answer 1

The correct option is C $\frac{v}{5}$

$mvr=\frac{nh}{2\pi }$, also $r=0.526n^2$

We can see $v$ is inversely proportion to $n$.

Also, $\frac{-13.6}{n^2}=-0.54$

$n=5$;

This gives: $v_5=\frac{v}{n}=\frac{v}{5}$