Lea (pronounced /ˈlɛd/) is a transitional element with a symbol Pb (Latin: plumbum). Lead has the atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish white color when freshly cut, but tarnishes to a dull grayish color when it is exposed to air and is a shiny chrome silver when melted into a liquid. Lead is used in building construction, lead-acid batteries, bullets and shot, weights, and is part of solder, pewter, and fusible alloys. Lead has the highest atomic number of all stable elements, although the next element, bismuth, has a half-life so long (longer than the estimated age of the universe) it can be considered stable. Like mercury, another heavy metal, lead is a potent neurotoxin that accumulates in soft tissues and bone over time.