1. Electron Configuration
Building the Atom

2. Remember…
Atomic Number (Z) : the number of protons in
the nucleus of the atom.
Mass Number (A) : the number of protons and
neutrons in the nucleus of the atom.
Neutron Number (N) : A - Z = N

3. LOCATION OF ELECTRONS IN THE ATOM:
Electron Cloud
Energy Levels
Sublevels
Orbitals

4. LOCATION OF ELECTRONS IN THE ATOM:
Sublevels have (degenerate states) that
we call orbitals.
These sublevels are named s, p, d, f, g, etc.
The energy level determines the number
of sublevels...

5. Sublevels: s- one orbital p- three orbitals d- five orbitals
LOCATION OF ELECTRONS IN THE ATOM:
Sublevels:
s- one orbital
p- three orbitals
d- five orbitals
f- seven orbitals
Etc...

6. It turns out, in each orbital, there
LOCATION OF ELECTRONS IN THE ATOM:
It turns out, in each orbital, there
can be a maximum of two electrons.
So...
s- 2 electrons total
p- 6 electrons total
d- 10 electrons total
f- 14 electrons total

7. 1s Orbital diagrams and electron configurations
Orbital diagrams help show how the electrons
are distributed within the sublevels.
NOTICE THAT WHEN
ELECTRONS PAIR
THEY HAVE OPPOSITE
SPINS. 1s

8. PAULI EXCLUSION PRINCIPLE...
No two electrons can have the same
quantum numbers or no more than
two electrons can be found in any
given orbital.

9. the most stable arrangement of electrons
HUND’S RULE:
the most stable arrangement of electrons
is that with the maximum number of unpaired
electrons, all with the same spin direction.
In other words…electrons don’t pair
until they have too!

10. Mg Orbital Diagrams What element is this???? 3s 2px 2py 2pz 2s 1s
etc...

11. Another way to write this is by using electron configuration notationMg
1s22s22p63s2

12. ORDER OF CHOICE: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s,
4f, 5d, 6p, 7s, 5f, 6d, 7p...
Why? Energy of some orbitals
overlap higher orbitals.
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13. end day 1 Let’s practice… Assignment:
Electron Configuration Level One and Two
Electron Configuration Wkst
end day 1

14. 1s remember...? Orbital diagrams and electron configurations
Orbital diagrams help show how the electrons
are distributed within the sublevels.
NOTICE THAT WHEN
ELECTRONS PAIR
THEY HAVE OPPOSITE
SPINS. 1s
remember...?

15. Mg remember...? Orbital Diagrams What element is this???? 3s 2px 2py
2pz 2s 1s
etc...
remember...?

16. Another way to write this is by using electron configuration notationMg
1s22s22p63s2
remember...?

17. [Ne]3s2 Mg Since Ne has a configuration of 1s22s22p6
Another way to write this is by using noble gas notation Mg
[Ne]3s2
Since Ne has a configuration of 1s22s22p6

18. Let’s practice…
Valence Electron Configuration

19. Connections:
Do you see any relationship between the
electron configuration and where the
element is located on the Periodic Table?

20. Let's do it! You should be able to… Write the electron configuration
Draw the orbital diagram
Write the noble gas notation
And predict the element
Let's do it!

21. Assignment:
Electron Configuration Wkst 2
end day 2