Which is not true of atoms? They are composed of molecules.

They make up all elements.

They are invisible.

They combine to form compounds.

The identities of substances are the same before and after which type of change

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.

A155.0 9 piece of copper at 182 °c is dropped into 2500 g of water at 23.9 °c. (the specific heat of copper is 0.385 1/9°c.) calculate the final temperature of the mixture. (assume no heat loss to the surroundings.)