Aaron conducted an experiment. He covered a pot of boiling water with a lid. The steam changed back to water. He concluded that- A. a physical change occurred

B. the chemical makeup of water changed

C. both physical and chemical changes occurred

D. there was no chemical or physical change

Iknow #2 is d. i just need to know why

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution?

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.