Caption：The important elements found in living cells are shown in color. The brown elements (CHNOPS) are the six abundant elements. The five essential ions are purple. The trace elements are shown in dark blue (more common) and light blue (less common.)
Notes：The five essential ions, in numerical order, are sodium, magnesium, chloride, potassium and calcium. The more common trace elements, in numerical order, are manganese, iron, cobalt, copper and zinc. The less common trace elements, in numerical order, are boron, fluorine, aluminum, silicon, vanadium, chromium, nickel, gallium, arsenic, selenium, molybdenum, tin and iodine.