What Determines the Valence of Transition Metals?

[z.js]

Judging from the electron configurations, it appears to me that all transition metals in their normal state have 2 valence electrons. If it isn't, what are the valences of the transition metals, why can they have many different valences, and what are the 1B-8B columns for?

Number of electrons in each energy shell:
Ar : 2, 8, 8
K : 2, 8, 8, 1
Ca : 2, 8, 8 , 2
(Transition Metals)
Sc : 2, 8, 9 , 2
Ti : 2, 8, 10, 2
V : 2, 8, 11, 2
Cr : 2, 8, 12, 2
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Zn : 2, 8, 18, 2
Ga : 2, 8, 18, 3---------and so on.

 

[DrClaude]

That's because the 3d electrons are listed before the 4s. The 4s orbital gets filled first, hence Ca is 4s², and then the 3d orbitals (the 4s being completely filled), hence Sc is 3d¹4s², and so on.

The d electrons are most definitely valence electrons and participate in bonding.