The proton mass is 1.007276 amu , the neutron mass is 1.008665 amu , and the electron mass is 5.486×10−4 amu . What is the expected mass of a sodium-23 nucleus, based on the total mass of its protons and neutrons?
Express your answer in atomic mass units using seven significant figures.

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

Compare and contrast physical changes with chemical changes.

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.