Allotropes

thumb|193x193px|Diamond and [[graphite are two allotropes of carbon: pure forms of the same element that differ in crystalline structure.]]

phase of hydrogen

molecular allotrope of phosphorus

deterioration of tin objects at low temperatures

Dilithium, Li2, is a strongly nucleophilic, diatomic molecule comprising two lithium atoms covalently bonded together. Li2 has been observed in the gas phase. It has a bond order of 1, an internuclear separation of 267.3 pm and a bond energy of 102 kJ/mol or 1.06 eV in each bond. The electron configuration of Li2 may be written as σ2.

allotrope of phosphorus

thumb|upright=1.5|(a) Scanning tunneling microscope|STM image of germanene. (b) Profile (black line in (a)) showing step heights of ~3.2  Å. (c) High-resolution STM image (distorted by sample drift). (d) Profiles along the white continuous and dashed lines in (c) showing a ~9–10  Å separation between protrusions having heights of ~0.2  Å. (e) [[Electron diffraction pattern. (f) Model of germanene on Au(111).]] Germanene is a material made up of a single layer of germanium atoms. The material is created in a process similar to that of silicene and graphene, in which high vacuum and high tempera

solid forms of the element phosphorus

form different types of steel

unstable allotrope of hydrogen

weakly bounded molecule consisting of three helium atoms

chemical compound

outdated concept for reactive hydrogen

six or seven different forms that pure plutonium metal can take