How do sky waves get reflected of ionosphere just because its lower frequency then space waves?



From what i understand Space waves penetrate ionosphere because of its high frequency but why is that?
And also how do lower frequencies such as skywaves NOT penetrate ionosphere?

In: Physics

Okay so the ionosphere is a unique layer of the atmosphere in that it has a permanent population of positively and negatively charged particles, meaning that it is actually a plasma rather than a gas. The type of waves you are talking about are electromagnetic waves, which consist of ripples in the electromagnetic field. When these ripples encounter charged particles, they are able to move them slightly, like buoys floating on top of a wavy ocean. Because positive and negative charges exist, when the wave hits they are moved in opposite directions, but their charge means that they attract one another. This attraction means that the disturbance from the wave is dampened out, so the wave slowly peters out and can’t travel through the plasma.

However, these charged particles are physical particles with their own mass, so there is a limit to how quickly they can move and change direction. If the EM wave frequency is higher than the frequency at which the particles can react to the changing field, then they won’t be able to dampen the wave and it will keep travelling.

Apologies, this might be a little technical for ELI5