Q. An electron jumps from an outer orbit to an inner orbit with an energy difference of 3.0eV. What will be the wavelength of the line emitted?
A) 3660 $\mathring{\mathrm{A}}$
B) 3620 $\mathring{\mathrm{A}}$
C) 4140$\ \mathring{\mathrm{A}}$
D) 4560 $\mathring{\mathrm{A}}$
Explanation
(c)
We know that the energy is emitted in the form of quanta and is given by,
$\mathrm{\Delta}E = hv = \frac{hc}{\lambda}$
or $\lambda = \frac{hc}{\mathrm{\Delta}E}$
$= \frac{6.62 \times 10^{- 27} \times 3 \times 10^{10}}{3 \times 1.6 \times 10^{- 12}}$
$= 4.14 \times 10^{- 5}$ cm
$= 4140\ \mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.