Easing Back Into Learning

We’re gonna take it nice and easy this first day back with a quick review of Electron Configurations and Orbital Diagrams that we left off with before we went on a week and a half hiatus. But! You can plan on having a quiz over these topics (and KLM diagrams) on Thursday.

To complete today’s assignment (the answers are posted BTW), you’ll need the following information about Orbital Diagrams. These are the rules that dictate where electrons go and how they spin.

1. Hund’s Rule: One electron is placed in each orbital of an electron shell BEFORE a second one is put in any of the shells.

    • Correct: ↑↓  ↑_   ↑_  ↑_  ↑_
    • Incorrect: ↑↓  ↑↓  ↑↓  __  __

2. Aufbau Principle: Each shell must be completely filled before beginning to fill the next shell

  • Correct: ↑↓      ↑_   ↑_  ↑_
  •              3s        3p
  • Incorrect: __    ↑↓  ↑↓  ↑_
  •                3s          3p

3. Pauli Exclusion Principle: Electrons in the same orbital spin in opposite directions

  • Correct: ↑↓
  • Incorrect: ↑↑

Electron Configuration – Tricks, Ions, & Shortcuts

There are three important pieces of information you will need to complete the Electron Configuration Worksheet from yesterday’s lesson.

1. Tricks

Lets do the Electron Configuration for 57Ce. It would look like this:EC Periodic Table1

Because ‘La‘ comes before ‘Ce‘, we have to add the 5d1 before we start counting the 4f orbital.


Now if we did the Electron Configuration for 72Hf, which is next to La, we have to go entirely through the 4f orbital before we go back to the 5d.EC Periodic Table2

BUT! When we do this, it would not make any sense to write 5d1 4f14 5d2

SO… we combine the 5d’s and place them after the 4f

2. Ions

Simple… if it’s a (-) then you add electrons to the final orbital.

9F is 1s2 2s2 2p5
9F-1 is 1s2 2s2 2p6

If its a (+) then you subtract electrons from the final orbital(s).

Na is 1s2 2s2 2p6 3s1
Na+ is 1s2 2s2 2p6           The 3s orbital has been lost!

3. Shorthand

This is the shortcut so you do not have to write out those huge-mungous (yes that is a word) electron configurations.
Lets do the electron configuration for Cl.

17Cl 1s2 2s2 2p6 3s2 3p5
The shorthand version uses the MOST RECENTLY PASSED NOBEL GAS (so when you pass gas use the shortcut… get it… c’mon that’s funny!) So for Cl, the most recently passed gas is Ne. So instead of starting at our ‘House’ (H), we’ll start at Ne and then count the orbitals from there.
17Cl [Ne] 3s2 3p5


Everybody loves somebody sometime
Everybody falls in love somehow
Something in your kiss just told me
That sometime is now
- Dean Martin

Today we’re announcing the launch of a brand new dating service… EHarmony!
Whats that? There already is an EHarmony you say? Well you didn’t read the fine print. Welcome to


Let me explain how it works. Lonely elements are looking for love and your going to help sign them up Dating Profile - Hydrogenfor this new dating service. You’ll create an online profile for them, a biography, and then a Video Dating Profile! Soon your element will be sharing their electrons and their lives with that special ion.To the left is an example of Hydrogen’s online dating profile. Directions and the profile template is available below and on the semester 2 docs page.

You will select your Element at Random. Once you have selected your element, add your first and last name in the approproiate row on this spread sheet. ( Element Spread Sheet – Google Doc ) Please do not adjust the names of other people as this document is open to everyone. At the end of the day I will close the document.

When you’re finished you’ll be able to view other element’s profiles and videos… you might even make a special connection that will mean something very special… I’m speaking of course, of BONUS POINTS. Good Luck!

Elemental Online Dating Instructions & Rubric

Online Dating Profile Template

March Madness… sort of

Unit 7 Test Prep Today we’ll be turning in our (gigantic) Limiting Reactants Packet.

Yes, you will have time to complete it in class.

Once you’ve completed your packet, you will be given a copy of the Unit 7 Practice Test. This test will be identical in setup, appearance, and expectation to the real Unit 7 Test on Tuesday March 5th

The answers will be posted today so you can check your work… however, the work will not be posted until Monday so you are not tempted to cheat. YOU MUST SHOW ALL WORK on the practice test and ON THE TEST.

In addition, I have posted information on the Board in Room 4335 (and below) to assist you in determining what information to put where in your table. YOU WILL BE GRADED BASED ON THE INFORMATION YOU PUT IN YOUR TABLE! So it’s important to learn how to discover numbers and where to place them.

Monday, we’ll be reviewing once more and there may even be an opportunity for Extra Credit. So study up and focus on Chem for a little while before you start thing bracketology.IMG_0136