Electron Configuration and
Orbital Diagrams
More fun stuff!
Electron Configurations!!
• Back to this from the other day: FIND IT!!
• It tells you what the electron configuration ends with…
Lovely. What Can I Do With It?
• We can write electron configurations!
• How do we do that?
– We find the number of electrons.
– We place them into orbitals, filling lower
energy to higher energy.
• Is there a chart to use?
– Indeed there is!!
Electron Configuration Chart
Great! How Do I Use It?
• Follow the arrows!
• How many electrons fit in s? 2
p? 6
d? 10
f? 14
• So you start at the top of the chart and fill in until
you run out of electrons!
• To note: the d orbital does not like to be almost
full or almost half full! Sometimes it steals
electrons from the previous s orbital!
Yeah, We’re Gonna Have to Practice
That…
• Let’s do Aluminum!
• Aluminum’s atomic # = 13
=13 protons: (no charge) = 13 electrons
So starting from the top of my chart:
Letters = shape and
max # of electrons
• Al: 1s2 2s2 2p6 3s2 3p1
=2
=4
=10
Big #s in front =
size of orbital
=12
=13
Exponents = # of electrons in
each orbital
= 13 electrons
You Do a Few!
•
Write the electron configurations for the
following atoms:
1. Lithium
2. Argon
3. Magnesium
Check It!
1. Lithium: Li: has 3 electrons
Li: 1s2 2s1
(2
3
= 3 total)
2. Argon: Ar: has 18 electrons
Ar: 1s2 2s2 2p6 3s2 3p6
(2
4
10
12
18
=18 total)
3. Magnesium: Mg: has 12 electrons
Mg: 1s2 2s2 2p6 3s2
(2
4
10
12
=12 total)
Can we do some with our partners?
• Yep.
• Do problems 1-5.
Noble Gas Electron Configuration
It’s like a shortcut….kind of….
•
•
•
Find the previous Noble Gas (Group 18).
Write brackets around it.
After the brackets, write the rest of the
electron configuration that isn’t included
in the noble gas.
Let’s See One!
•
•
•
•
Let’s do magnesium, Mg.
The Noble Gas before it is Neon.
So we write [Ne].
Then follow the periodic table from yesterday
until you get to Magnesium, so…
• Mg is in the 3s row, and I have to hop over 2
spaces to get there.
• So we add 3s2 after the noble gas, so we get:
[Ne] 3s2
I know it’s not on your notes, but…
• Let’s do Nitrogen, N.
Helium
• Previous Noble Gas?
• What do you have to go through to get
from He to N?
– 2s2 AND 2p3
• So we end up with [He] 2s2 2p3
Can we do this one with our
partners?
• Yep.
• Do problems 6-10.
More fun with Electrons!
• Orbital Diagrams: show the different
electrons in each sublevel of each orbital:
• Uses the same concept of electron
configuration, except this one has fun
boxes showing sublevels!
• 2 electrons per sublevel=2 electrons per
box.
Yeah, I’m Gonna Need to See That…
• For instance, let’s do Oxygen:
• Oxygen (atomic # 8) has 8 electrons:
– What would be electron configuration
notation?
– O: 1s2 2s2 2p4
• So orbital diagram would look like this:
Note: You want an arrow going up in each box before
you put arrows pointing down!
You Do One
• What would be the orbital diagram for
Bromine??
Check It!
• Bromine, Br (atomic# = 35) no charge, so
there are 35 electrons.
• Electron configuration would be:
Br: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
(2
+2
+6
+2
+6
+2
+10
+5
= 35 total)
And now we will draw it on the board!
Let Me Guess: We’re doing these
with our partners, too?
• You got it!
• Do problems 11-15 and check all the
answers before turning it in.
• Wait for everybody to get done before we
start lab.