About: http://webisa.webdatacommons.org/258075317

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	M is a hydrogen atom or an alkali metal, such as sodium, potassium and lithium, or the equivalent of an alkaline earth metal, such as, for example, of calcium, but in particular is an alkali metal.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es