[enzzz]

Okay, I was wondering what makes gold a precious metal as it is.. Looking at the electron configuration I noticed it has 2)8)18)32)18)1)..
It means it's filled like this:
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d10
Take a look at 6s1.. Why is it 6s1 not 6s2? What makes the difference, because my logic would say it must be 6s2, also noticed the same case with Platinum :O. Then it would make it 2)8)18)32)17)2), but it isn't. Could anyone tell me why? Thank you.

[cliverlong]

I would guess something similar to the behaviour of the 3d and 4s orbitals described here

http://www.chemguide.co.uk/inorganic/transition/features.html

where one electron is promoted from a "full" 4s orbital to make a half-filled 3d⁵ or full 3d¹⁰ orbital.

Clive