Question

If the velocity of an electron in 1${}^{st}$ orbit of H atom is V, what will be velocity of 3${}^{rd}$ orbit of Li${}^{2+}$?

• A. V
• B. V/3
• C. 3V
• D. 9V

Answer 1

Answer: (A)

V

$V\propto \frac{Z}{n}$
Hence, $\frac{V_H}{V_{Li2+}}=\frac{Z_H}{n_H}\times \frac{n_H}{n_{Li2+}}=\frac{1}{1}\times \frac{3}{3}=1$
Hence, the velocity of third orbit of $L{i}^{2+}$ will be V.