1. Topic 2 Atomic Structure
Electronic Configuration
s, p, d, f orbitals

2. “s” orbitals
An “s” orbital is spherical in shape and the size of the sphere depends on the energy level it is found in.
ie. The 2s orbital would be smaller in size than the 4s orbital when filled with electrons.
An “s” orbital can hold 2 electrons only

3. Visual representation of an “s” orbital

4. p orbitals
A “p” orbital is dumbell shaped. Due to the shape of this orbital there is a dimensional component which must be considered.
Each “p” orbital is divided into 3 sub shells which can each hold 2 electrons for a total of 6 in a single “p” orbital

5. Visual representation of a “p” orbital

6. d orbitals
Starting at scandium (atomic #22) there are so many electrons to keep in order around a nucleus that a “d” orbital is observed to maintain order.
**Note**
The first “d” orbital does not take place until you reach period 4. However it is assigned as the 3d orbital. Don’t forget!!!
d orbitals can hold a total of 10 electrons.

7. Visual representation of a “d” orbital

8. Overlay of d orbitals

9. f orbitals (not needed in IB-11)
Once you reach Cerium (atomic #58) there are too many electrons to store in s, p, and d orbitals.
At this point an “f” orbital is observed to maintain order.
**Note**
The first “f” orbital is not observed until you reach period 6. However it is assigned as a 4f orbital.
Each “f” orbital can hold 14 electrons.

10. Visual representation of “f” orbitals

11. Overview s,p,d,f orbitals

12. Filling order

13. It follows the periodic table!

14. You might find this useful
“n” would represent the period number

15. Some examples of what it looks like

16. IB-11 must go up to “Kr” #36
This view of electron arrangement is a more advanced model offering a more realistic view of what has been observed experimentally in chemistry to date.

17. Exceptions to the rule
There are two exceptions IB students need to be aware of
Chromium and Copper
Both promote an electron from the 4s to the 3d orbital.
This is due to half and full orbitals being especially stable configurations!