Question

An electron changes its position from orbit $n = 4$ to the orbit $n = 2$ of an atom. The wavelength of the emitted radiation’s is (R = Rydberg’s constant).

• A. $\frac{16}{R}$
• B. $\frac{16}{3R}$
• C. $\frac{16}{5R}$
• D. $\frac{16}{7R}$

Answer 1

Answer: (B)

$\frac{16}{3R}$

Answer 2

$\frac{1}{\lambda} = R\left\lbrack \frac{1}{n_{1}^{2}} - \frac{1}{n_{2}^{2}} \right\rbrack = R\left\lbrack \frac{1}{(2)^{2}} - \frac{1}{(4)^{2}} \right\rbrack$ ⇒ $\lambda = \frac{16}{3R}$.