Chemistry

Problem

Frequency of a photon emitted due to transition of electron of a certain element from

L

K

shell is found to be

4.2 \times 10^{18} \text{ Hz}

. Using Moseley's law, find the atomic number of the element, given that the Rydberg's constant

R = 1.1 \times 10^7 \text{ m}^{-1}