The Franck-Hertz experiment accelerated electrons in a mercury vapor tube and measured the current at the collector, demonstrating: a. the line spectra of mercury, consistent with the Bohr model.
b. the discrete energy levels of the atom, consistent with the Bohr model.
c. elastic and inelastic collisions of electrons with mercury atoms.
d. all of the above.

The frequency of a given region of the electromagnetic spectrum ranges from 3 × 1016 − 3 × 1019 hertz. which type of wave is found in this region? a. x-rays b. ultraviolet rays c. infrared waves d. radio waves

Road users moving into your lane, brake lights, and abrupt changes in road surface are a. rare at night b. indicators of potential hazards c. not worth worrying about before you reach them d. no problem for experienced drivers

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? a. the ice dissolves oxygen from the air, forming a denser crystalline matrix.b. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds.c. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer.d. the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer.