Which UV light does not reach the Earth's atmosphere?

UVC is indeed the type of UV light that does not reach the Earth's atmosphere. This is due to its shorter wavelength and higher energy, which makes it more likely to be absorbed by atmospheric gases, particularly ozone. The ozone layer effectively filters out UVC radiation, preventing it from reaching the surface.

On the other hand, UVA and UVB radiation can penetrate the atmosphere and reach the Earth, with UVA being less intense but more prevalent, while UVB has a higher energy level and is responsible for causing sunburns. Due to this atmospheric filtering capability, UVC is effectively nullified in terms of reaching the Earth's surface, which is why it is understood as the type of UV light that doesn't make it through the atmosphere.