-------+------------+------------+------------+------------+- Series.|Zero group. | Group I. | Group II. | Group III. | -------+------------+------------+------------+------------+- 0 | _x_ | —— | —— | —— | | | | | | 1 | _y_ | Hydrogen. | | | | | H = 1.008 | —— | —— | | | | | | 2 | Helium. | Lithium. | Beryllium. | Boron. | | He = 4.0 | Li = 7.03 | Be = 9.1 | B = 11.0 | | | | | | 3 | Neon. | Sodium. | Magnesium. | Aluminium. | | Ne = 19.9 | Na = 23.05 | Mg = 24.1 | Al = 27.0 | | | | | | | | | | | | | | | | 4 | Argon. | Potassium. | Calcium. | Scandium. | | Ar = 38 | K = 39.1 | Ca = 40.1 | Sc = 44.1 | | | | | | | | | | | | | | | | 5 | —— | Copper. | Zinc. | Gallium. | | | Cu = 63.6 | Zn = 65.4 | Ga = 70.0 | | | | | | | | | | | | | | | | 6 | Krypton. | Rubidium. | Strontium. | Yttrium. | | Kr=81.8 | Rb = 85.4 | Sr = 87.6 | Y = 89.0 | | | | | | | | | | | | | | | | 7 | —— | Silver. | Cadmium. | Indium. | | | Ag = 107.9 | Cd = 112.4 | In = 114.0 | | | | | | 8 | Xenon. | Cæsium. | Barium. | Lanthanum. | | Xe = 128 | Cs = 132.2 | Ba = 137.4 | La = 139 | | | | | | 9 | —— | —— | —— | —— | | | | | | | | | | | | | | | | | | | | | 10 | —— | —— | —— | Ytterbium. | | | | | Yb = 173 | | | | | | | | | | |