Final answer:
The electromagnetic spectrum covers all electromagnetic radiation types, ordered by wavelength from largest to smallest: ELF waves, FM radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Step-by-step explanation:
The electromagnetic spectrum encompasses a vast range of electromagnetic radiation types, characterized by their different wavelengths and frequencies. Understanding what is the electromagnetic spectrum is crucial in Physics as it provides insight into the various forms of electromagnetic radiation that exist. The electromagnetic spectrum is ordered from the largest to the smallest wavelength as follows: Extremely Low Frequency (ELF) waves, FM radio, microwaves, infrared, visible light (with red having a longer wavelength than green), ultraviolet, X-rays, and finally, gamma rays. This order reflects a decrease in wavelength and an increase in frequency, which means energy increases as you move from ELF waves to gamma rays.
Each type of electromagnetic radiation has unique properties and uses. For instance, microwave radiation is employed in microwave ovens and some communication devices, while X-rays are widely used in medical imaging. Gamma rays, being the most energetic, are used in medical treatments such as radiotherapy and also originate from cosmic phenomena.