Chemical element cubic centimeter (g/cm). Since several elements are gases at commonly encountered temperatures, their densities are usually stated for their gaseous forms; when liquefied or solidified, the gaseous elements have densities similar to those of the other elements. When an element has allotropes with different densities, one representative allotrope is typically selected in summary presentations, while densities for each allotrope can be stated where more detail is provided. For example, the three familiar allotropes of carbon (amorphous carbon, graphite, and diamond) have densities of 1.8–2.1, 2.267, and 3.515 g/cm, respectively. The elements studied to date as solid samples have eight kinds
Element collecting element in everyday use. Some are averse to collecting the element as a compound or alloy, while others find this acceptable. Collectors may isolate elements in their own homes. Hydrogen, for example, can be easily isolated via the electrolysis of water. In addition to the element samples, some element collectors also collect items connected with the element, such as manufactured goods containing the element, rocks and minerals with the element as a constituent or compounds of the element. Some manufacturers also sell coins made from pure elements, and density cubes made from the pure element can also be sourced on