Which statement best describes how a Geiger counter works? Select one:
a. Water vapor condenses along a path traveled by ionizing radiation.
b. Particles ionized by radiation cause black streaks to appear on sensitive photographic paper.
c. Radioactive particles ionize argon gas in a tube and the resulting electric current is amplified and heard as a clicking sound.
d. A material sensitive to radioactive emissions glows when mixed with a radioactive substance.

The small bags of silica gel you often see in a new shoe box are placed there to control humidity. despite its name, silica gel is a solid. it is a chemically inert, highly porous, amorphous form of sio2. because water vapor readily adsorbs onto the surface of silica gel, it acts as a desiccant. despite not knowing mechanistic details of the adsorption of water onto silica gel, from the information provided you should be able to make an educated guess about the thermodynamic characteristics of the process. predict the signs for δg, δh, and δs for the adsorption of water.