2.2 ActivitiesRemember1. Chemical formula equation often are used to represent the chemicals involved, the physical states of the chemicals are included, and the numbers are written in front of the formulas in order to balance the number of atoms on each side of the equation2. Symbols are used to show the physical states of chemicals (s, l ,g)3. An aqueous solution is obtained when a substance is dissolved in waterThink1. Fe(II), Hg, Zn, Al2. C6H8O7 + Na2CO3 + saliva => C6H5O7Na3 + CO2 + H2O3. It is necessary to balance chemical equations because the reactants and products must both have an equal amount of atoms, or have an equal ratio of atoms