Central Concept: Oscillating electric or magnetic fields can generate electromagnetic waves over a wide spectrum.
6.1 Recognize that electromagnetic waves are transverse waves and travel at the speed of light through a vacuum.
When electric and magnetic fields vibrate they create a wave that moves perpendicular to their vibrations. See model demo here. The wave is a disturbance in the electric and magnetic fields and does not require matter to carry that energy. Unlike other vibration waves, electromagnetic waves do not require a medium; in fact, e-m waves travel fastest in a vacuum with nothing in its way.
Example MCAS question for 6.1
6.2 Describe the electromagnetic spectrum in terms of frequency and wavelength, and identify the locations of radio waves, microwaves, infrared radiation, visible light (red, orange, yellow, green, blue, indigo, and violet), ultraviolet rays, x-rays, and gamma rays on the spectrum.
The electromagnetic spectrum is the range of electromagnetic waves that we deal with in physics. They are usually ordered from low frequency and long wavelength to high frequency and short wavelength.