[appleseed]

Hiya

So the definition of a transition metal is a partially filled d orbital, but Im confused as to whether its partially filled when its an ion?

ok that's my first question
and also I dont underdstand why scandium isnt a transition metal , electron configuration Sc: [Ar] 4s2, 3d1,

i checked the net, and it said that scandium looses 3 e- and therefore has no e- in its d shells, but why is it that it looses 3 electrons, why couldnt it loose 2 of its 4s electrons?

because Zinc is also not a transition metal because it has a full d orbital, but thats not even when its an ion?


Thank you very much for all help !! 

[tamim83]

It is better to call scandium and zinc d-block metals.  This means, to me, that when writing an electron configuration for these metals following the Aufbau principle, the last sub-shell that gets filled is a d subshell.  This of course is for writing electron configurations for neutral atoms, not ions.  The ions formed by a metal indicates its chemical reactivity.  Because scandium has three valence electrons (4s², 3d¹), its chemistry is very similar to the group 13 elements (its predominant oxidation state is +3).  The difference is that the third valence electron is in a d orbital and not a p orbital.  This is why scandium is placed in the d-block (or transition metal section).  Transition metals have d electrons in their valence electron configurations as neutral atoms. 

A similar thing with zinc.  Since zinc has a full 3d subshell, it behaves like a group 2 metal chemically (i.e.-it forms +2 ions). But it is still considered a transition metal. 

The way that the periodic table is organized is often contested because the criteria changes over time.  Mendeleev ordered the elements by atomic mass and chemical reactivity.  The modern periodic table is ordered mostly using electron configurations (Aufbau style) which explains chemical reactivity as well. 

Hope that helps some.