1. Electromagnetic waves are produced by oscillating electric charges, which generate oscillating electric and magnetic fields that propagate away from the charges as transverse waves. 2. The speed of electromagnetic waves is constant in vacuum. Frequency and wavelength are inversely related, with higher frequencies having shorter wavelengths. 3. Examples of electromagnetic waves include radio waves, microwaves, visible light, x-rays, produced by oscillating charges at different frequency scales from circuits to atomic nuclei.