Electron configuration question

When transition metals become ions, they lose their 4s electrons before their 3d electrons- is this the same for all elements?

I thought all elements lost 4s first but in my text book it said it was 'unusual' for this to happen.

E.g. Ca is 1s2 2s2 2p6 3s2 3p6 4s2
and Ca2+ is 1s2 2s2 2p6 3s2 3p6

so has lost its 4s electrons before 3d? just checking as what it said in my text book made me second guess myself?

What spec are you on as the answer to the question could depend on your exam board?

It means unusual if it's got s and p electrons. Clearly group 1 & 2 elements have no 'p' electrons to lose so they lose 's' electrons when ionised.

1st row transition metals lose 4s before 3d, BUT Ga, Ge etc. lose 4p before 4s

AQA

When transition metals become ions, they lose their 4s electrons before their 3d electrons- is this the same for all elements?

I thought all elements lost 4s first but in my text book it said it was 'unusual' for this to happen.

E.g. Ca is 1s2 2s2 2p6 3s2 3p6 4s2
and Ca2+ is 1s2 2s2 2p6 3s2 3p6

so has lost its 4s electrons before 3d? just checking as what it said in my text book made me second guess myself?

for both transition metals and non transition metals you fill 4s electrons before 3d electrons first as usual ( just like saying you fill (n+1)s electrons first before (n) d electrons from a algebraic point of view) which means 4s comes before 3d and that 4s electrons are lower in energy than the 3d electrons.

however when we ionise (so remove e-): the 4s electrons are lost first before 3d, this is a phenomenon as this now implies that 4s electrons are higher in energy than 3d electrons, which contradicts the above paragraph as 4s electrons are lower in energy than the 3d electrons (in other words, somehow the 4s electrons come after 3d electrons so they "magically" swapped positions), allbeit a small difference. Note that this only applies to transition metals.

if we ionise non transition metals, then the 4s electrons are lost after 3d electrons.

Thanks so much! But referring to the example in my original post it appears that calcium still loses the 4s electrons first? Never realised I didn't understand this until I've thought about it in so much detail!

I would love to quote everyone in, but I neither have the l33t skillz nor the time.

I hate to be the bearer of bad news for some...

https://www.chemguide.co.uk/atoms/properties/3d4sproblem.html#top