Answer to Question #202111 in Optics for Prachi

Question

Two energy levels of an atomic system are separated by energy corresponding to frequency 5.0×10¹⁴ Hz. Assume that all atoms are in one or the other of these two energy levels. Compute the fraction of atoms in the upper energy level at temperature 600 K. Take k_b = 1.38×10^-23JK^-1 and h=6.6×10^-34Js.

Answer 1

$\frac{n_1}{n_2}=\frac{h\nu}{kT}=\frac{6.63\cdot 10^{-34}\cdot 5\cdot 10^{14}}{1.38\cdot 10^{-23}\cdot 400}=0.4.$