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
All elements test relied on to meet this test. All elements test The all elements rule or all limitations rule (often written with a hyphen after "all") is a legal test used in US patent law to determine whether a given reference shows that a patent claim lacks the novelty required to be valid. The rule is also applicable to an obviousness analysis. Under the rule, a single reference (for anticipation) or the combination of references relied upon, plus the ordinary knowledge of persons skilled in the art (for obviousness), must provide each claimed element. For anticipation, and under certain circumstances for obviousness,