Chemists use chemical equations to describe the materials that are present before and after a chemical reaction occurs. Reactants, products, coefficients and subscripts are terms used to describe chemical equations. Duration: 6:45.
Based on the principle of the conservation of mass, atoms are neither created nor destroyed in a chemical reaction. A chemical equation reflects with principle when it is balanced such that the number of atoms present as reactants equals the number of atoms found as products. Duration: 8:40.