Lithium be cut with a knife. When cut, it possesses a silvery-white color that quickly changes to gray as it oxidizes to lithium oxide. While it has one of the lowest melting points among all metals (180 °C), it has the highest melting and boiling points of the alkali metals. Lithium has a very low density (0.534 g/cm), comparable with pine wood. It is the least dense of all elements that are solids at room temperature; the next lightest solid element (potassium, at 0.862 g/cm) is more than 60% denser. Furthermore, apart from helium and hydrogen, it is less dense than
Lightest Supersymmetric Particle scatter light and thus not be "dark". They must also almost certainly be non-colored. With these constraints, the LSP could be the lightest neutralino, the gravitino, or the lightest sneutrino. In extra-dimensional theories, there are analogous particles called "LKP"s or "Lightest Kaluza-Klein Particle". These are the stable particles of extra-dimensional theories. Lightest Supersymmetric Particle In particle physics, the lightest supersymmetric particle (LSP) is the generic name given to the lightest of the additional hypothetical particles found in supersymmetric models. In models with R-parity conservation, the LSP is stable; in other words, the LSP cannot decay into any Standard Model particle,