Be -Hg- is a chemical element with atomic number 80. Mercury is also known as quicksilver or hydrargyrum. Mercury is the only metal that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine. With a freezing point of −38.83 °C and boiling point of 356.73 °C, mercury has one of the narrowest ranges of its liquid state of any metal. A heavy, silvery d-block metal, mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, and some electrical switches.