When both sides have the same amount of elements of each type. For example, the equation CaCO3 + HCl -> CaCl2 + H2O + CO2 is not balanced. This is because there are 2 Cl's on the right side, and only one on the left. So you would put a 2 in front of the HCl to get 2 Cl's on both sides. read more
It means that in any reaction mass should neither be created nor be destroyed, total mass of reactants should be equal to total mass of products, and also the number of one type of atoms should not change. read more
A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge are the same for both the reactants and the products. In other words, the mass and the charge are balanced on both sides of the reaction. read more