Dissolving salt in water causes a CHEMICAL change. true or false

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.

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same

Which statement can best be concluded from the ideal gas law?