·http://www.youtube.com/watch?v=JNPFR22MPA
·http://www.chemguide.co.uk/atoms/propertie
s/atomorbs.html
·http://www.chemguide.co.uk/atoms/propertie
s/orbitsorbitals.html#top
·http://www.chemguide.co.uk/atoms/propertie
s/elstructs.html#top
1
What Does an Atom Look Like?
Draw what you think N looks like in the box
below...
What is wrong with this diagram? What do the circles really represent?
3
Why have we been taught
circles...and that electrons travel
in perfect orbits?
·Circles are not actually wrong, they are just misrepresented when they
are taught by some people.
·The truth is that circles are meant to represent energy levels of the
electrons around the nucleus, not necessarily the paths the "follow"
around the nucleus.
·As electrons get further and further away from the nucleus, they have
more and more energy, because they are less "drawn in" by the nucleus.
Here is what electron clouds in an Atom really look like...
http://www.youtube.com/watch?v=sMt5Dcex
0kg
Electrons travel in Subshells, known as Orbitals. These are not ORBITS, but they
are ORBITALS. The electron has a 95% probability that it is within its designated
orbital
Heisenberg Uncertainty
Principle
·Says, loosely, that you can't know with certainty
both where an electron is and where it's going
next.
·What it actually says is that it is impossible to
define with absolute precision, at the same time,
both the position and the momentum of an
electron.)
4
Types of Subshells
P orbitals can hold 6 Electrons
S orbitals can hold 2 Electrons
S orbitals can hold 2 Electrons
S orbitals can hold 2 Electrons
6
Electrons orbitals are represented by 4 shapes (S,P,D,F)
p
s
group # = # valence (outside)
8A
e3A 4A 5A 6A 7A
1A
1
2A
d
2
Row 3
=
4
# shells
5
3B 4B 5B 6B 7B 8B 8B 8B 1B 2B
s
p
d
6
7
6
f
7
f
Notice something different with d?
We Can represent the # of electrons in their
shells in what is called- Electron
1s1
Configuration
row # = shell
#
possibilities
are 1-7
7 rows
subshell-
group # = # valence
epossibilities are:
s: 1 or 2
p: 1-6
s, p, d, or
d: 1-10
f
f: 1-14
4
Total e- should
subshells equal
Atomic #, Why?
Lets try and figure out what shells are in Cl?
Subshells d and f are “special”- They are each staggered by
one row. So for row 4, they are actually 3d, not 4d!
group # = # valence
e-
1A
1
2A
period # = # eshells
2
3
3B 4B 5B 6B 7B 8B 8B 8B 1B 2B
4
3d
4d
5d
6d
5
6
7
d
6 4f
7 5f
f
8A
3A 4A 5A 6A 7A
Try and write them out in order, you can stop with 6s.
Order of Electron Subshell Filling:
It does not go “in order”, you read the periodic table from left to
right.
1s
2s2
2p6
3s2
3p6
4s2
3d
4p6
5s2
4d
5p6
6s2
4f 5d
The Electrons in an atom can be show with letters and numbers (Electron Configuration), or also with
boxes (Ground State Configuration). They show the same information, just a different representation.
·Electrons are
represented here in
boxes with up and down
arrows.
·Electrons will try and
"space" out in the
available boxes, so you
fill them one at a time.
·Electrons like their
space because their
charges repel each
other.
10
Practice:
Ask these questions every time you have to write an
electron configuration
·Lithium:
·find the element on the periodic table
·what is the period number?
2
·how many shells?
·what is the group number?
·how many valence electrons?
·what subshell(s) does Li have?
·what is the electron configuration?
2
1
1
s
2
1s 2s1
Now it can get annoying to write out all of these Electron Configuration for the elements
further down on the periodic table! So fortunately there is a shortcut! Instead of writing it all
out, you can first write the name of the "last" Nobel gas in brackets, and then do the
Electron Configuration from there.
First Draw the Electron Configuration for Zn...
Watch this video, it is basic, but really helps break down the steps...while
watching the video, think of how YOU could make it better, because that
will be your project for the rest of the week!!!
http://www.youtube.com/watch?v=JNPFR22MPA