Zinc, sometimes called spelter, [4] is a chemical element. It is in the group of metals called the transition metals. It is sometimes considered a post-transition metal. Its symbol on the periodic table is "Zn". Zinc is the 30th element on the periodic table, and has an atomic number of 30. Zinc has a mass number of 65.38. It contains 30 protons and 30 electrons. In total, 29 isotopes of zinc are known, and five of these occur in nature. Some isotopes are radioactive. Their half-lives are between 40 milliseconds for 57Zn and 5x1018 years for 70Zn. Zinc is a metal that is mostly used for galvanizing and batteries. It is the fourth most common metal used by people. Properties[change | change source]Physical properties[change | change source] Zinc is a shiny bluish grey metal. When it has just been cut, zinc has a whitish-grey color. If it is exposed to air, it will not stay shiny for long. Its melting point is (419.58 °C (787.24 °F)), and its boiling point is (907.0 °C (1, 664.6 °F)). This temperature is lower than most transition metals but higher than tin or lead. It can be melted on a cooking stove. It boils at a low temperature for a metal.[5] It is not magnetic. When heated a little, it becomes very flexible. If it is heated more, it becomes very brittle.[6] It forms alloys easily with other metals. Chemical properties[change | change source] Zinc is a reactive metal. It is about as reactive as aluminium and more reactive than most of the more common metals, such as iron, copper, nickel, and chromium. It is less reactive than magnesium. Zinc can react with acids, bases, and nonmetals.[7] It does not rust in air, though. A coating of zinc oxide and zinc carbonate forms on the surface of the zinc when it is in air.[8] This coating stops corrosion. Acids can dissolve this coating and react with the zinc metal.[9] This reaction of zinc with an acid makes a zinc(II) salt such as zinc chloride and hydrogen gas. This is a very common chemical reaction. The reaction below is the react