If an electron in an atom moves from an energy level of 5 to an energy level of 10:. a. a photon of energy 5 is absorbed.
b. a photon of energy 15 is absorbed.
c. a photon of energy 5 is emitted.
d. a photon of energy 15 is emitted.

Taylor's experiment: 1. accurately measured the speed of light 2. locked together the phases of two light sources so that the interference pattern would not shift 3. showed that man's reaction time was much slower than the speed of light 4. showed that individual photons have wave characteristics

What is the most useful equation for electric power?

The electric field inside a cell membrane is 8.0mn/c. what's the force on a singly charged ion in this field?