PLEASE HELP

Noble gases are commonly used in gas discharge tubes commonly known as "neon signs". What causes the light produced in these signs?

A. excited electrons falling back to the nucleus

B. electrons being excited to higher energy levels then returning to their original energy level

C. gases reacting with the glass of the sign due to being electrified

D. electricity giving the atoms greater vibrational energy

The diagrams to the right show the distribution and arrangement of gas particles in two different containers. according to kinetic-molecular theory, which of the following statements is true? check all that apply. if the temperatures of both containers are equal, container a has greater pressure than container b. if the volume of container a decreased, its pressure would decrease. if the pressure in both containers is equal, container a has a lower temperature than container b.