Question

What are the radiation types in order from lowest to highest energy:
Microwaves, ultraviolet light, red light and gamma rays?

Answer 1

Hint: In the above question we are asked to arrange the given electromagnetic radiations in the order of their increasing energies. The energy of an electromagnetic radiation is proportional to the frequency of the radiation and inversely proportional to the wavelength. First we need to know the frequency or the wavelength of the above given radiation and accordingly we can classify them in the order of their increasing energies.

Complete step-by-step solution:
Let us say we have an electromagnetic radiation of frequency $\gamma $. If we denoted Planck's constant by ‘h’, then the energy ‘E’ of the radiation is given by,
$E=h\gamma $
The frequency range of the above electromagnetic radiations are as follows:

Electromagnetic radiation	$\gamma $ (frequency range)
Microwaves	${{10}^{9}}Hz-{{10}^{12}}Hz$
ultraviolet light	${{10}^{16}}Hz-{{10}^{17}}Hz$
red light	$4\times {{10}^{14}}Hz$
gamma rays	${{10}^{18}}Hz-{{10}^{22}}Hz$

From the above table we can conclude that the above electromagnetic radiations in the order of their increasing frequencies can be classified as,
Microwaves < ultraviolet light < red light < gamma rays
Since the energy of the above electromagnetic radiation is proportional to the frequency of the radiation, the arrangement of the increasing order of energies of the above given radiations is,
Microwaves < ultraviolet light < red light < gamma rays

Note: It is to be noted that the energy of the radiation is inversely proportional to the wavelength. Hence if we arrange the above radiations in the order of their increasing wavelength, then the order will correspond to the arrangement of their respective energies in decreasing order. It is also to be noted that these radiations are obtained from the transition of the electrons in an atom as they jump from higher energy state to lower energy state.