Question

electromagnetic waves vary in _____ and ______.

medium

wavelength

frequency

speed

Explanation:

Electromagnetic waves are characterized by varying wavelengths (distance between wave crests) and frequencies (number of waves per second), as described by the wave equation \( c = \lambda
u \) (speed \( c \) is constant in a vacuum, so wavelength and frequency are inversely related). Medium affects speed but is not a defining variable of the wave itself, and speed is constant in a given medium.

Answer:

wavelength, frequency