According to most scientists, cold fusion
will not be a practical source of energy on earth.
would be a practical source of energy on earth if it were less expensive.
will be a practical source of energy on earth within the next few decades.
will always continue to be a practical source of energy on earth.

i know the answer is not c or b

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.