When iron is added to HCl, 720 cm3 of hydrogen is produced. What is the mass of iron used? Fe(s) + 2HCl(aq) → FeCl2(aq) + H2 (g)

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.