Boric acid is the name according to the traditional nomenclature. Boric acid is formed by the addition of three molecules of water to the boric oxide. The valence of boron is 3, and the valence of oxygen is 2, so boric oxide is B2O3. Now add three molecules of water: B2O3 + 3 H2O = H6 B2 O6 = H3 B O3. Then, the answer is that the formula that stands for boric acid is H3 BO3.