Ultraviolet rays from the sun are able to reach earth's surface because a. they require air to travel through b. they have less energy than infrared rays c. they have lower frequencies than visible light d. they can travel through empty space

Sound is a disturbance that travels through a medium as a

Describe cytokinesis in plants and animals. in animals: in plants.

The nuclear potential that binds protons and neutrons in the nucleus of an atom is often approximated by a square well. imagine a proton conned in an innite square well of length 105 nm, a typical nuclear diameter. calculate the wavelength and energy associated with the photon that is emitted when the proton undergoes a transition from the rst excited state (n 2) to the ground state (n 1). in what region of the electromagnetic spectrum does this wavelength belong?