Electron Configuration

[eduardomorales5]

So how does Lavelle want us to write the electron configuration of transition metals? Like for instance Vanadium, does he want us to write it like [Ar]4s2 3d3 or [Ar]4s1 3d4?

[vpena_1I]

Vanadium's electron configuration would be written [Ar]3d3, 4s2. Remember 3d has lower energy than 4s, so it is written first. You would only take electrons from the s orbital if it's to complete a half-full or full d subshell, as in the instance of Cr:[Ar]3d5,4s1.

[chrisleung-2J]

You should always write the electron configuration in numerical order, with lower principal levels preceding higher ones.

[Jasmine Kim 1L]

Vanadium's electron configuration would be written [Ar]3d3, 4s2. Remember 3d has lower energy than 4s, so it is written first. You would only take electrons from the s orbital if it's to complete a half-full or full d subshell, as in the instance of Cr:[Ar]3d5,4s1.

A good way to remember this is to just take electrons from the s orbital for the 4th and 9th element in the d orbital, just before all the subshells are full.