Balancing of equations as shown in the attached document requires that the number of atoms, of an element, on the left of the equation is equivalent to the number of the atoms of the same element on the right of the equation. This is in observation of the conservation of mass rule of thermodynamics. Mass and energy cannot be destroyed nor created, it can only be transformed from one form to another. In this case, mass remains the same in the system since this is a chemical reaction- only the bonds between atoms are being rearranged.
