Longer wavelength means lower frequency and lower energy. There is no simple relationship because different photons travel at different speeds. X rays have higher energy than radio waves. X rays have higher frequency than radio waves. X rays and radio waves are both forms of light, or electromagnetic radiation.
X rays have shorter wavelengths than radio waves.
X rays travel through space faster than radio waves. We can see each other in the classroom right now because we emit visible light. When an electron in an atom goes from a higher energy state to a lower energy state, the atom can absorb a photon of any frequency. If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces X rays. When white light passes through a cool cloud of gas, we see an absorption line spectrum.