Refraction.
Light behavior in which light goes through a medium and bends, going in a different direction.
Reflection.
Light behavior in which light waves bounce off a medium and goes in a different direction.
Concave.
A surface shaped in such a way that the center curves inward like this:
Convex.
A surface shaped in such a way that the center curves outward like this:
I just took the test I hope this helps. :)
