Orbitals

Question 1

in what order do we fill atomic orbitals

Answer 1

orbitals with the lowest energy fill up first,
also
fill all the orbitals of the same sub-shell singiuraly before you pair them up

Question 2

order of energy level in sub-shells (order of electrons filling them)

Answer 2

1s , 2s , 2p , 3s , 3p , 4s , 3d , 4p

All in order but only 3d and 4s have switched around so electrons would fill up the 4s orbital before filling up the 3d orbitals in the 3d subshell

Question 3

what is the order you write electron configuration

Answer 3

in order of subshells not in order off filling
so when writing configuration 3d subshell will be written before 4s even though 4s is off a lower energy so is filled first

Question 4

what are the elements that are exceptions to the electron configuration rules

Answer 4

chromium and copper
remember crinkly cucumber

Question 5

how are chromium and copper exceptions

Answer 5

important point; the 3d subshell is much more stable when it is half full or fully full so both chromium and copper will give electrons from their 4s sub-shell to achieve this

both want a more stable 3d sub-shell
so therefore chromium should end 3d4 4s2
but instead it wants a half full 3d sub-shell so it looses one electron from its 4s shell and adds it to the 4d subshell
so it chromium ends
3d5 4s1 (3d5 is a half full 3d subshell so thats much more stable than 3d4)

with copper it can gain a full 3d sub-shell by giving one electron from its 4s subshell so it would be
from ending with 3d9 4s2 and it would change to 3d10 4s1

Question 6

what do chromium and copper want which makes them differ from others and give their electrons to the 3d sub-shell

Answer 6

chromium wants a half full 3d sub-shell so looses an electron from its 4s which results in ending 3d5 4s1 instead off 3d4 4s2

copper wants a full 3d sub0shell and can achieve this by removing an electron from its 4s subshell and putting it in the 3d subshell
which results in an ending of 3d10 4s1 instead of 3d9 4s2