Well red blood cells carry oxygen to muscles
Circulatory system is probably the answer you are looking for.
The number of neutrons in an atom is the number of particles present in its nucleus.
The atomic number is the number of protons whereas the mass number is the number of protons and number of neutrons together
This implies that the number of neutrons is the atom's mass number
Stoichiometry is the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers. Hoped this helped!!!!. Also if you are trying to look for the formulas it should be online just type in stoichometry formulas.