Why do sand, snow, pavement, grass, etc. reflect UV rays?

Question

what are other things or surfaces that reflect UV rays?

i need detail as in atoms (wat happens in them)

Answer 1

I think the question is what allows the electromagnetic radiation to penetrate a particular material and what makes it to bounce off (to reflect). To better appreciate this question we have to look at a behavior of light as an electromagnetic wave (EMW) coupled with an atomic/molecular nature of matter. The transparency of the material depends on atomic architecture. For example, atoms form a grid as in a crystalline structures and are properly spaced to allow EMW to pass without interference make the material transparent.
On one side we have the atomic architecture on the other we have the parameter the EMW such as frequency. UV has a higher frequency than IR and X-rays are even of a higher frequency than UV. This is why X-rays are moving through matter we otherwise see as opaque.

Considering wave aspects of EMW and the geometry (architecture) of materials such as sand, ice crystals or anything else helps us understand why some material reflect, refract and absorb some frequencies while being opaque to others.

I hope that helps.

Answer 2

Any material that will not accept the high energy UV rays will reflect them.