Question

Name the rays or waves of highest frequency.
A). X – rays
B). UV rays
C). IR rays
D). Gamma rays

Answer 1

Hint: Students can solve this problem by recalling the electromagnetic spectrum. The electromagnetic spectrum is a series of the different types of electromagnetic radiations arranged in ascending order of their increasing frequencies. The required answer will be the rays that are on the end of the electromagnetic spectrum with greatest frequency.

Complete step by step answer:
According to the electromagnetic spectrum, the waves of highest frequency are Gamma rays. The average frequency of Gamma rays is ${10}^{22}\text{ Hz}$. Since there is a direct correlation between the energy and penetrating power of electromagnetic radiation with their frequency, it can be said that Gamma rays carry the highest amount of energy and have the greatest penetrating power in the electromagnetic spectrum.
Gamma rays are released during nuclear reactions. They have no mass or charge, but are made up of pure energy particles known as photons.
Hence, the correct option is D) Gamma rays.

Additional information:
Due to their high energy and penetrating power, gamma rays are used for killing germs and for sterilizing some surfaces. They are also used for killing cancerous cells and destroying them.

Note: Students must have at least the names of the waves in the correct order of the electromagnetic spectrum properly memorized, even if they are not able to keep in mind the corresponding frequencies. Knowing the proper electromagnetic series is key in solving such types of questions.
The electromagnetic spectrum can be memorized by the use of clever mnemonics. One such mnemonic is “Raging Martians Invaded Venus Using X-ray Guns”, where the underlined letters stand for Radio waves, Microwaves, Infrared radiation (IR), Visible region, Ultraviolet radiation (UV), X-rays and Gamma rays in the proper ascending order of their increasing frequencies.