Which substance is a combination of different atoms?

homogeneous mixture
heterogeneous mixture
element
compound

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.

Which of the following is not true about the atomic model of substances?

The chemical name for laughing gas is dinitrogen oxide. the two elements found in a sample of this gas are and