light

Question 1

reflection?

Answer 1

wave travels in one medium strikes the surface of another medium and changes direction so that it returns back to the medium

Question 2

law of reflection?

Answer 2

states incident angle (i) and reflected angle (r) are always the same

Question 3

refraction?

Answer 3

speed at which a wave travels is dependent upon the medium in which it travels along or through

Question 4

refractive index?

Answer 4

denser medium has large refractive index..
light travels slowly in media with higher indicies..

OR GOOGLE SAYS
a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density.

Question 5

Concave lens?

Answer 5

causes light rays to diverge or spread out