This quantity is related to the number of particles times mean polarizability by the Lorentz-Lorenz equation. This quantity can be (-5[1])negative in left-handed metamaterials. (10[2]-5[1])This quantity changes linearly in response to an electric field in Pockels effect, and it changes quadratically with the electric field in the Kerr effect. Taking the arctangent of the ratio of two values of this quantity gives Brewster’s angle. The ratio of two values of this quantity equals (10[1])the ratio of the sines of two (10[1])angles in Snell's (-5[1])law. (10[1])For 10 points, dividing the (10[1])speed of light by the speed of light in a medium gives what quantity that measures how much light bends in a medium? ■END■ (10[2])