Electron Orbitals and
Division 2 MST
While we go through this PowerPoint, I
will be taking notes on the board
You should write down what I write on the
You should also have out your periodic
what you need to know
Electrons orbit the nucleus
Electrons have energy
Electrons are arranged in a specific pattern
Electrons will fill energy levels closest to the
nucleus first, and then fill those further away
Closest = 1 N=2
Next = 2
Next = 3 ….
The only problem with
this model, is that only
the electrons in the s
orbital, circle the
So what do the electron orbitals really look like?
Each of the Energy Levels has
At Energy level = 1
The only orbital
fit in this
What happens when we have
more than 2 electrons?
They go to a higher energy level
At Energy level = 2
The possible orbitals are s and p
Energy level = 2
sublevels = s and p
Electrons will fill the S sublevel first
What do you notice about p
you think the
Okay, but there are elements with
more than 8 electrons…
Electrons will then fill Energy level 3
which has 3 possible orbitals…
you think the
d orbitals could
Electrons must occupy the lowest energy
An orbital can hold up to 2 electrons, but
they must have opposite spins
Orbitals of equal energy are each occupied
by 1 electron before others are doubled up.
Let’s take an example
How many electrons does Carbon have?
What would be the first energy level to fill?
Now what orbital does the first energy
How many electrons will fit?
What happens next?
The N=2 energy level will start to fill
What are the orbitals in the N=2?
s and p
Which one will fill first?
How many electrons will go into the s orbital?
How many electrons are now left?
Where do they go?
Our last rule
must each be
can double up
How do we represent this without
using the orbital diagrams?
Electron Configuration 1s22s22p6
(do you know which element is represented?)
Practice makes perfect!
Let’s practice some of these….
Write the electron configuration and orbital