IB Chem., 3/9/09IB Chem., 3/9/09Good Sub note/ Friday’s homeworkGood Sub note/ Friday’s homework

Tests…Tests…

Lab Friday, Computers MondayLab Friday, Computers Monday

Finally a websiteFinally a website

Electron configurationsElectron configurations

HomeworkHomework

Good Sub Good Sub Note/Friday’s Note/Friday’s

homeworkhomeworkI’ve never had 3 days worth of good sub I’ve never had 3 days worth of good sub notes so, I’ll find something easy to do notes so, I’ll find something easy to do at some point this year. Maybe a movie at some point this year. Maybe a movie or somethingor something

I didn’t expect that you would get to I didn’t expect that you would get to the assignment from the book on Fridaythe assignment from the book on Friday

Therefore we aren’t going to worry Therefore we aren’t going to worry about the homework very muchabout the homework very much

TestsTestsIf you haven’t taken the test yet, it will If you haven’t taken the test yet, it will turn into a “0” after school Fridayturn into a “0” after school Friday

You can still take it any time for full You can still take it any time for full credit but the “0” will be a friendly credit but the “0” will be a friendly reminderreminder

Finally a Finally a website…website…

I have finally begun work on a websiteI have finally begun work on a website

The goal is to post PowerPoints of lessons and The goal is to post PowerPoints of lessons and whatever assignments I have available in digital whatever assignments I have available in digital formform

This is a great place to go if you are absent, lose This is a great place to go if you are absent, lose copies of an assignment or would like a copy of copies of an assignment or would like a copy of my notesmy notes

Please be aware, nothing beats being in class. Please be aware, nothing beats being in class. My notes and assignments change over the My notes and assignments change over the course of the day and the most up-to-date form course of the day and the most up-to-date form may not always make it to the websitemay not always make it to the website

ElectronsElectronsWhy bother talking about electrons?Why bother talking about electrons?

What did electrons have to do with…What did electrons have to do with…Atomic radius?Atomic radius?Ionization energy?Ionization energy?Electronegativity?Electronegativity?Electron affinity?Electron affinity?

Much of the periodic table is set-up based on Much of the periodic table is set-up based on electrons but it is useful for more then the electrons but it is useful for more then the number of electronsnumber of electrons

Make sure you have a periodic table to look at Make sure you have a periodic table to look at NOW!NOW!

Electron Electron configurationsconfigurations

Electron orbitals come in 4 flavors: s, p, d & Electron orbitals come in 4 flavors: s, p, d & ff

What different? The number of electrons What different? The number of electrons each holds, how much bigger then H it is each holds, how much bigger then H it is and the shapeand the shape

How many electrons do each hold?How many electrons do each hold?An s orbital holds 2 electronsAn s orbital holds 2 electrons

A p orbital holds 6 electronsA p orbital holds 6 electrons

A d orbital holds 10 electronsA d orbital holds 10 electrons

An f orbital holds 14 electronsAn f orbital holds 14 electrons

ShapesShapesEach orbital has it’s own very Each orbital has it’s own very distinctive shapedistinctive shape

We’ll worry more about this later and I We’ll worry more about this later and I will provide pictures so don’t even will provide pictures so don’t even bother to try and draw thesebother to try and draw these

Click here

Weird!Weird!

Filling OrbitalsFilling OrbitalsIn order to write an electron In order to write an electron configuration we need to know the configuration we need to know the number of electrons an atom has. number of electrons an atom has. Where do we get this information?Where do we get this information?

Second we need to know the order that Second we need to know the order that we fill the orbitals and what orbitals are we fill the orbitals and what orbitals are being filled in orderbeing filled in order

Filling OrbitalsFilling OrbitalsThis is a lot of numbers but they all This is a lot of numbers but they all tend to be usefultend to be useful

For example the electron configuration For example the electron configuration of Magnesium (Mg), look like:of Magnesium (Mg), look like:

Mg: 1sMg: 1s222s2s222p2p663s3s22

How do we determine the order?How do we determine the order?

Filling OrbitalsFilling Orbitals

Do you think there may be some exceptions?Do you think there may be some exceptions?

Filling OrbitalsFilling OrbitalsThe orbitals fill in order by the arrows. The orbitals fill in order by the arrows. Written in order, they look like:Written in order, they look like:

1s2s2p3s3p4s3d4p5s4d5p6s4f5d6p7s5f6d7p1s2s2p3s3p4s3d4p5s4d5p6s4f5d6p7s5f6d7p

Oh my!Oh my!

I think you would rather remember it I think you would rather remember it based on the diagram on the last slidebased on the diagram on the last slide

The last slide is referred to as the The last slide is referred to as the “diagonal rule”“diagonal rule”

Using the Using the diagramdiagram

The configuration for nickel (Ni):The configuration for nickel (Ni):

Try writing a configuration for each of the Try writing a configuration for each of the following:following:

Li, O, Ne, PLi, O, Ne, P

What about an ion? If a configuration depends What about an ion? If a configuration depends on the number of electrons, can we figure out on the number of electrons, can we figure out how many electrons an ion has? The how many electrons an ion has? The configuration for Sconfiguration for S2-:2-:

How about the configuration for AlHow about the configuration for Al3+3+? F? F-?-?

HomeworkHomeworkWrite the electron configurations for the Write the electron configurations for the follow:follow:

Atoms: Cs, Se, Cd, U, PbAtoms: Cs, Se, Cd, U, Pb

Ions: IIons: I--, O, O2-2-, K, K++, Fe, Fe3+3+

Compare the configurations of SeCompare the configurations of Se2-2- and Kr and Kr