Period 6 element deposited later by meteorites which contained the element. This supposedly explains why, in prehistory, gold appeared as nuggets on the earth's surface. Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum ( < Greek "" "water" and "" "silver"). A heavy, silvery d-block element, 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, though metals such as caesium, francium, gallium, and rubidium melt just above room temperature. With a freezing
Interstitial element Interstitial element An interstitial element is an impurity found in "pure" metals or crystals. The quantity of these elements affect the physical properties of the host material. They can be introduced during the manufacturing process. The most common interstitial elements in metals are hydrogen, carbon, nitrogen, and oxygen. These elements are small enough to fit between normal crystalline lattice locations. In contrast, those elements that replace locations in the crystalline structure are called substitutional elements. An example of the effects of interstitial elements on metal properties can be found in grade 1–4 titanium. Although the grades 1–4 are considered commercially