I) Calculate the volume of hydrogen gas
produced at s. t.p., when 30g of zinc is
added to excess dilute hydrochloric acid
at 33°C and 775 mmHg pressure.
H = 1, Zn = 65, Cl = 35.5) molar volume
of a gas at s. t.p. = 22.4 dm').

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.