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Topscore test 3 gc #1
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When adding electrons you add to 4s then 3d. This is because 3d is higher in energy than 4s when empty. Once 4s and 3d fill up though it is different. The 3d drops in energy and is more stable than 4s. So when removing electrons you remove from the 4s before the 3d.
Additional input... draw the standard e- config for Zn first.
[Ar] 4s2 3d10 - now to go to its cation (lose 2e-) you ALWAYS take e from the higher #'d orbital (4 > 3)
[Ar] 4s0 3d10
[Ar] 4s2 3d10 - now to go to its cation (lose 2e-) you ALWAYS take e from the higher #'d orbital (4 > 3)
[Ar] 4s0 3d10
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I thought this was only for Cr, Mo, Cu, Ag, and Au.. according to Chad's video. I guess it's like that for all transition element then?
Well..if you look at the normal state - it has a full 3d subshell - it wants to keep the 3d subshell - therefore it takes the electrons from the lower energy 4s subshell.
You always want to form the most stable electron configuration - and the ones that really matter are d5 and d10...that's why chad mentions them, because they do it to a far greater degree than filling an s shell or half fill a p shell or fully fill a p shell.
Keep in mind..if you're talking p's...half filling a p makes it more stable, and fully filling the p makes it even more stable, it's just that half filling or fully filling a d shell is far greater/more important
If you notice, both the 4s and 3d subshells are full normally for Zn...then it loses two electrons. Now make the most stable electron configuration...it's kind of logical
Which would be more stable?
[Ar]4s2 3d8 - 2 unpaired e-
[Ar]4s0 3d10 - no unpaired e- however empty p orbitals - much more stable.
This is why when you make a cation, take the highest #'d shell's electrons (4s)
Now for ground-state substances (non-ionic) same logic can apply
Let's look at Cu - which is more stable
[Ar] 4s2 3d9 - 1 unpaired e-
[Ar] 4s1 3d10 - 1 unpaired e- however it half fills the 4s subshell, and full 3d subshell - much more stable.
You always want to form the most stable electron configuration - and the ones that really matter are d5 and d10...that's why chad mentions them, because they do it to a far greater degree than filling an s shell or half fill a p shell or fully fill a p shell.
Keep in mind..if you're talking p's...half filling a p makes it more stable, and fully filling the p makes it even more stable, it's just that half filling or fully filling a d shell is far greater/more important
He's also mentioning it for ground state, not ionic substances.
If you notice, both the 4s and 3d subshells are full normally for Zn...then it loses two electrons. Now make the most stable electron configuration...it's kind of logical
Which would be more stable?
[Ar]4s2 3d8 - 2 unpaired e-
[Ar]4s0 3d10 - no unpaired e- however empty p orbitals - much more stable.
This is why when you make a cation, take the highest #'d shell's electrons (4s)
Now for ground-state substances (non-ionic) same logic can apply
Let's look at Cu - which is more stable
[Ar] 4s2 3d9 - 1 unpaired e-
[Ar] 4s1 3d10 - 1 unpaired e- however it half fills the 4s subshell, and full 3d subshell - much more stable.
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