How do I figure out the number of shells in noble gas items?

[LoveKnowledge]

I am confused? Do I look at somewhere on the periodic table? For example for the noble gas items argon, radon, helium, and neon?

 

[LoveKnowledge]

I hope that I posted this in the right section as well..

 

[mathman]

If you look at the periodic table, then the number of completed shells corresponds to the order as you go down the list. Helium - 1, Neon - 2, Argon - 3, etc.

 

[JDługosz]

See http://en.wikipedia.org/wiki/Electron_configuration" . The first illustration shows what you are interested in. Note the specific elements you want are along the right edge.