Answer:
The law of conservation of mass states that mass cannot be created nor destroyed.
Step-by-step explanation:
In terms of chemical equations, in a basic reaction, the amount of mass produced in the products must be the same as the amount of mass of the inital reactions. Therefore, we must balance chemical equations in order to fulfill law of conservation of mass. For example, if H2 + O2 -> H2O, you must add a 2 coefficient to balance the equation in order for the equation to obey the law of conservation of mass. Therefore, it must be 2H2 + O2 -> 2H2O. 4 hydrogens and 2 oxygens go in, and 2 water molecules come out (4 hydrogens, 2 oxygens).