What causes your skin to feel warm when it is in the sun on a summer day? A Particles in the atmosphere reflect energy from the Sun downward.
B Hot particles from the Sun still carry some heat when they reach your skin.
C The solar wind carries heated air from the Sun's atmosphere to Earth's surface.
D The Sun radiates energy that passes through space and the atmosphere to your skin.

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.