Electrons the whirling things around nucleus. Almost no mass normally an atom has the same number of electrons as protons. Periodic Table at Los Alamos Periodic Table Simplfied Atomic Mass or Weight. The Alkali Fluxes and the Alkaline Earth Fluxes have the clearest relationships on the table. The center of the table contains most of the colorants, and the right side of the table contains the glass formers modifiers and other miscellaneous glaze elements.
Many ceramic materials contain more than one element.
Clays contain mostly silica and alumina. Feldspars contain silica, alumina , and fluxes. Dolomite contains Magnesia and Calcia. A concept you don' t need to know except to understand old ceramic texts.