[dipz04]

I was taught to use the Aufbau principle for electron config.
For Example:
Ti----> [Ar] 4s² 3d²

But in my book it says
Ti----> [Ar] 3d² 4s²

Does it matter what way you put the sub-level?

[willian921]

i think it does because electrons go from a lower energy level first before it can achieve a higher level. therefore 4s is lower than 3d, which means 4s needed to be listed first. consult your teacher to see what he/she has to say.

[dipz04]

Thanks 
that does make more sense but i'll my teacher just in case.

[Borek]

Nitpickers may disagree but the way I see it order in which you list orbitals doesn't matter - it doesn't carry any additional information. Or at least, there is no convention I am aware off that will make the order meaningful.

[dipz04]

ok thanks 

[DemonicAcid]

Order is supposed to be lowest energy level first, but when stabilization effects come into play orbitals don't always have a fixed position in relation to each other. So it's more of a general idea than a hard rule.

[maksitude95]

Its just a convention to go in increasing order of principal quantum numbers