Uranium has numerous physical, chemical and atomic properties that make it useful for a wide range of uses such as energy production and weapons design. Uranium's primary use is as a source of energy in nuclear reactors, though it is only weakly radioactive and requires a moderator, such as heavy water, to effectively generate heat.
Apart from its use in energy production, uranium can be used as the fissile trigger in nuclear weapons. Antitank ammunition is often made from depleted uranium because of its high density and its ability to transfer impact energy to modern armor. Uranium's high density makes it very heavy, per unit volume, and the metal is often used as a counterweight in aircraft flight surfaces. It is also used in the construction of aircraft gyroscopes.
Uranium has chemical properties that make it valuable to several industries. In the 19th century, oxidized uranium was used as an additive in the manufacture of colored glass. Uranium has been detected in glass that dates to the early Roman Empire, where it was used to impart a golden yellow hue to high-quality glass. The use of uranium in glassware largely came to an end after it was discovered that uranium glass emits alpha radiation.