A macroelement or quantity element is a mineral substance that occurs in different media in a mass fraction of more than 50 mg/kg. Its counterpart is the microelement or trace element. Quantity elements are mostly present in an ionized form in an aqueous medium, i.e. as particles that are positively charged (Na+, K+, Ca2+, Mg2+) or negatively charged (Cl-, HPO42-, SO42-). That is why they are also called electrolytes.