The chemical symbol for mercury is "Hg." This symbol is derived from the Latin word "hydrargyrum," which means "water-silver," reflecting the element's silvery appearance and liquid state at room temperature. Mercury is a unique metal known for its high density and ability to conduct electricity. It has various applications, including in thermometers, barometers, and some types of batteries. Despite its usefulness, mercury is also toxic, posing environmental and health hazards. Because of its potential dangers, many countries have regulations regarding its use and disposal, raising awareness about safer alternatives.