the industrial production of hydroiodic acid takes place by treatment of iodine with hydrazine N2H4: 2I2 + N2H4 = 4HI + N2 a) how many grams of I2 needed to react with 36.7 g of N2H4? b) how many grams of HI are produced from the reaction of 115.7 g of N2H4 with excess iodine?

Which of these conditions most likely produces an unstable isotope?

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.

Describe what happens to the molecules as water goes from ice to liquid to vapor. be sure to explain what happens to the temperature during the phase changes.