What are the three properties that all electromagnetic waves share?
It’s tough to know what you’re going for here. All waves have descriptive properties of speed, wavelength, and frequency which are related by the equation v = lambda x nu, where v = speed, lambda = wavelength, and nu (sometimes the letter ‘f’ instead of the Greek letter nu) = frequency. For electromagnetic waves, the speed is constant and equal to the speed of light, c. Naturally, the specific values of wavelength and frequency can change from one wave to another. This is what distinguishes radio waves from light waves or even one color of light from another. A more advanced and fundamental answer is that the speed of light (which applies to all electromagnetic waves, whether they appear as visible light or not) can be derived as: c = 1 / sqrt(mu_0 x epsilon_0) where mu_0 is the magnetic permiability of free space and epsilon_0 is the permittivity of free space. This relates three fundamental properties of the universe and is independent of wavelength or frequency. Or, you could go in
