We are given the volume of a graduated cylinder and asked for the mass when it is empty. The simplest way to just weight the empty graduated cylinder. If the cylinder is already filled with liquid, simply convert it to mass using its density. Then, weight the full cylinder and subtract the masses.
most of the positively charged particles should bounce back at a range of angles as they collide with the atoms in the foil; only a few should pass straight through the foil
