Zinc is a metallic element, number 30 in the periodic table with the symbol Zn. It is a shiny white metal with a blue-gray luster, tarnishes in moist air and burns in air with a bright bluish-green flame. Zinc is the fourth most common metal in use, trailing only iron, aluminum, and copper in annual production. Over half of the consumption is to galvanize steel to prevent corrosion and it is used in many alloys especially in brass and bronze. It is also used as a micronutrient in agriculture.