S C Kheterpal, S N Dhawan and, P N Kapil Solutions for Chapter: Structure of Atom, Exercise 3: PROBLEMS FOR PRACTICE

Which has a higher energy: a photon of red light with a wavelength of $7500 \mathrm{Å}$ or a photon of green light with a wavelength of $5250 \mathrm{Å}?$

In the ultraviolet region of the atomic spectrum of hydrogen, a line is obtained at $1026\mathrm{}\mathrm{Å}.$ Calculate the energy of photon of this wavelength $\left(\mathrm{h}=6.626\times {10}^{-34}\mathrm{J}\mathrm{}\mathrm{s}\mathrm{e}\mathrm{c}\right).$

In the infrared region of the atomic spectrum of hydrogen, a line is obtained at $3802 \mathrm{c}{\mathrm{m}}^{-1}.$ Calculate the energy of this photon $\left(\mathrm{h}=6.626\times {10}^{-34}\mathrm{J} \mathrm{s}\right).$

Light of wavelength $4000 \mathrm{Å}$ falls on the surface of caesium. Calculate the energy of the photoelectron emitted. The critical wavelength for photoelectric effect in caesium is $6600 \mathrm{Å}$.

What is the ratio between the energies of two radiations, one with a wavelength of $6000\mathrm{}\mathrm{Å}$ and the other with $2000\mathrm{}\mathrm{Å}\left[1\mathrm{Å}={10}^{-10}\mathrm{m}\right]?$

The threshold energy for photoelectric emission of electrons from a metal is $3.056\times {10}^{-15}$ joule. If light of $4000 \mathrm{Å}$ wavelength is used, will the electrons be ejected or not? $\left(\mathrm{h}=6.63\times {10}^{-34} \mathrm{Js}\right).$

Calculate the wavelength of a photon in Angstrom units having energy of one electron volt.

Sodium street lamp gives off a characteristic yellow light of wavelength $588 \mathrm{n}\mathrm{m}.$ Calculate the energy per mole $\left(\mathrm{i}\mathrm{n} \mathrm{k}\mathrm{J}/\mathrm{m}\mathrm{o}\mathrm{l}\right)$ of these photons.