system
Given the following post, respond as if you're commenting on Reddit:
human
Why radiowaves can travel through walls, microwaves/visible light can't, but x-rays/gamma rays need lead walls to get blocked ?
gpt
It's all about what frequencies the material resonates at, and whether or not it is a conductor.  Radio waves have a long wavelength and low energy.  The low energy means that they won't be able to excite resonances in most atoms and molecules.  Their long wavelength allows them to pass around most conducting sources in a wall without being grounded out.  On the other hand, you could easily block all radio waves as well  by just running connected wires spaced a foot or so apart all the way around and turning the room into a simple Faraday cage.

With microwaves and visible light, you start getting into energy levels that can excite vibrations, and so they are able to be absorbed, and thus blocked.

As you keep moving to higher frequencies, the photon energies get much higher, high enough that a single vibration doesn't contain enough energy to completely absorb them, or the energy is enough to completely ionize a molecule and then be re-released.  Because of that, you need a very dense material able to absorb a lot of energy in order to block them.