In a chemical reaction, the mass of the products must equal the mass of the_ _ _ _. Elements Reactants Atoms Molecules

In the millikan oil drop experiment they determined that every drop had a charge which was a while number multiple of -1.60x10^-19. if a drop has a total charge of -9.60x10^-19 then how many excess electrons are contained within the drop?

What will most likely happen when two bromine atoms bond together?

Which method would be best to separate a mixture of sand and gravel