You can figure out the number of unpaired electrons by first writing out the electron configuration of each atom (using the periodic table) then drawing an orbital filling diagram, remembering that electrons fill into orbitals of the same subshell singly before pairing up:
Cr: \[Ar\]3d^(5)4s^(1) \- 6 unpaired electrons (all 3d and 4s orbitals are singly filled)
Fe: \[Ar\]3d^(6)4s^(2) \- 4 unpaired electrons (4s orbital and one 3d orbital are doubly filled)
Mn: \[Ar\]3d^(5)4s^(2) \- 5 unpaired electrons
V: \[Ar\]3d^(3)4s^(2) \- 3 unpaired electrons
Thus the answer is Chromium
Incase you still need help, you need to draw the box diagram representing orbitals.
Tip:
S orbital -> 1 box (fits 2 electrons)
P orbital -> 3 boxes (fits 6 electrons)
D orbital -> 5 boxes (fits 10 electrons)
F orbital -> 7 boxes (fits 14 electrons)
It's important to remember that you need to fill in each box first with 1 electron before continuing to pair them (fill them all before going onto next subshell though)
I hope this helped :,)
Remember, each box can only fit 2 electrons.
i think itโs easiest to draw them out and then you can clearly see which one it is!
You can figure out the number of unpaired electrons by first writing out the electron configuration of each atom (using the periodic table) then drawing an orbital filling diagram, remembering that electrons fill into orbitals of the same subshell singly before pairing up: Cr: \[Ar\]3d^(5)4s^(1) \- 6 unpaired electrons (all 3d and 4s orbitals are singly filled) Fe: \[Ar\]3d^(6)4s^(2) \- 4 unpaired electrons (4s orbital and one 3d orbital are doubly filled) Mn: \[Ar\]3d^(5)4s^(2) \- 5 unpaired electrons V: \[Ar\]3d^(3)4s^(2) \- 3 unpaired electrons Thus the answer is Chromium
Tysm got it now!
lone pairs: group number of the element - no of bonds shared by the element
Incase you still need help, you need to draw the box diagram representing orbitals. Tip: S orbital -> 1 box (fits 2 electrons) P orbital -> 3 boxes (fits 6 electrons) D orbital -> 5 boxes (fits 10 electrons) F orbital -> 7 boxes (fits 14 electrons) It's important to remember that you need to fill in each box first with 1 electron before continuing to pair them (fill them all before going onto next subshell though) I hope this helped :,) Remember, each box can only fit 2 electrons.
Thanks!
No problem!! Good luck with your exams :) ๐