Why did the model of the atom change? A. New materials became available to build better models.
B. The structure of atoms changed over time.
C. Scientists did not like the original model.
D. Experiments provided new evidence about the atom.

The rock in a lead ore deposit contains 89 % pbs by mass. how many kilograms of the rock must be processed to obtain 1.5 kg of pb?

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.

Amedication is given at a dosage of 3.000 mg of medication per kg of body weight. if 0.1500 g of medication is given, then what was the patient's weight in pounds (lbs)? there are 453.59g in 1 lb.