What is the part of the cartridge that actually flies outward (the projectile)?

True, the standard unit for volume is liters which can be represented by either a lower case "l" or a capital "l"

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom