Single Idea 17413

[catalogued under 27. Natural Reality / E. Chemistry / 3. Periodic Table]

Full Idea

The modern notion is that atoms fall into the same group of the periodic table if they possess the same numbers of outer-shell electrons.

Gist of Idea

Elements in the table are grouped by having the same number of outer-shell electrons

Source

Eric R. Scerri (The Periodic Table [2007], 07 'Quantum')

Book Reference

Scerri,Eric R.: 'The Periodic Table' [OUP 2007], p.192


A Reaction

Scerri goes on to raise questions about this, on p.242. By this principle helium should be an alkaline earth element, but it isn't.