State the law of reflection, describe refraction as bending between media, and explain absorption in terms of color.
Light reflects off most surfaces following one rule: the angle of incidence equals the angle of reflection, both measured from the normal, a line perpendicular to the surface. A beam aimed at a mirror at 30 degrees from the normal bounces off at 30 degrees on the other side.
Refraction is light bending as it passes between media, like air into water, because it changes speed -- this is why a straw in water looks bent at the surface. Absorption happens when a material takes in certain wavelengths instead of reflecting them; a red shirt reflects red wavelengths and absorbs the rest, and a black shirt feels hotter in sunlight because it absorbs most wavelengths as heat.
Mastery looks like: They apply the law of reflection to find a reflected angle, and explain refraction and absorption using real examples.
Common stumbles: Measuring angles from the mirror's surface instead of the normal line; thinking a colored object "makes" its own color rather than reflecting existing light.