Question

in a certain atom the last electron has a 3d2 electron configuration write the electron configuration of the element using a noble gas as a core

Answer 1

So for example if they gave us: Ti2+

I would write the noble gas electron configuration like this [Ar] 3d2 4s2

And then just take away 2 e- from the last number you wrote 4s2

-Your noble gas electron configuration for Ti2+ then would be: [Ar] 3d2