electromagnetic spectrum
#1 -
#2 - Gamma rays, x-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, radio waves.
#3 - Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays, gamma rays
#4 - No, electromagnetic waves do not need a medium. Just look at astronauts. They communicate through radios because, while sound cannot travel through space, radio waves can. The same goes with light - light from the Sun travels across space and to Earth, without a medium.
#3 - Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays, gamma rays
#4 - No, electromagnetic waves do not need a medium. Just look at astronauts. They communicate through radios because, while sound cannot travel through space, radio waves can. The same goes with light - light from the Sun travels across space and to Earth, without a medium.