The element mercury conducts electricity. It can be used to construct position dependent switches that are silent. Manufacturers also use mercury in fluorescent lights and advertising signs.
Mercury is a metal that exists as a liquid at room temperature. It derives its chemical symbol, Hg, from the Greek word "hydrargyrum," which means "liquid silver."
Mercury produces light in a florescent lamp when electricity passes through the element's vapor, creating short-wave ultraviolet light and causing the phosphor in the lamp to fluoresce. While mercury is a good conductor of electricity, it is also highly toxic. Mercury that enters the body can accumulate over time and potentially result in severe illness or death.