Simple Browser : Welcome guest : log in
Home |  Graph |  ]  KB:  Language:   

Formal Language: 



KB Term: 

  Francium

Sigma KEE - Francium

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Francium
Radioactive element, belongs to group 1 of the periodic table. Found in uranium and thorium ores. The 22 known isotopes are all radioactive, with the most stable being Fr-223. Its existence was confirmed in 1939 by Marguerite Perey.
Relationships      
Parents ElementalSubstance The Class of PureSubstances that cannot be separated into two or more Substances by ordinary chemical (or physical) means. This excludes nuclear reactions. ElementalSubstances are composed of only one kind of atom. Examples: Iron (Fe), copper (Cu), and oxygen (O_2). ElementalSubstances are the simplest PureSubstances.


Show full definition (without tree view)
Show full definition (with tree view)

Show without tree


Sigma web home      Suggested Upper Merged Ontology (SUMO) web home
Sigma version 3.0 is open source software produced by Articulate Software and its partners