Question

what is the best definition of an electromagnetic wave? an electromagnetic wave is a transverse wave that has electrical and magnetic properties. an electromagnetic wave is a longitudinal wave with electricity. an electromagnetic wave is a mechanical wave.

Explanation:

Electromagnetic waves are transverse waves. They consist of oscillating electric and magnetic fields perpendicular to each other and to the direction of wave propagation. Mechanical waves require a medium (like sound in air), but electromagnetic waves can travel in a vacuum. Longitudinal waves have particle - displacement parallel to wave - direction (e.g., sound), while electromagnetic waves are transverse.

Answer:

An electromagnetic wave is a transverse wave that has electrical and magnetic properties.