Chem 11 – Class Starter1. Please take out your Periodic Table “cut-ups” and place them on

your table2. If this makes more sense, why are periodic tables laid out the

way they are?• Practicality…

Soon… this “alternative” model of the Periodic Table will become very important to us…

Intro to Quantum Mechanics• Video

Where were were…?• Collect the Quantum Revolution Worksheet from the

front of the room• In about 8 minutes we will review as a class

Unfortunately…• Bohr’s model on worked for

one specific molecule…Hydrogen

• So what’s so unique about Hydrogen?

One electron system• We can’t have a model that

works for only one ATOM!

One more thing… Waves vs. Particles1. Is light a wave or a

particle?2. Is an electron a wave or

a particle?

BOTH ARE BOTH!?!

Wave-Particle Duality

Finally…. the MODERN MODEL of the atom

It took several years, several scientists, and some outside the box thinking to develop the current model of the atom…

Video: NOVA - Quantum Mechanics - Probability Density

If you had to make a bet (non monetary of course) on finding a specific person, when you have no prior knowledge of where they live, where in BC would you

choose?

Population Density of BC

Bohr Theory

The electron is a particle that must be in orbital in the atom.

Quantum Theory

The electron is like a cloud of negative energy or a wave.

Orbitals are areas in 3D space where the electrons most probably are.

The energy of the electron is in its vibrational nodes- like notes on a guitar string.

Photons are produced when high energy nodes change to lower energy nodes

We now not only have shells…• We now have subshells within shells…

• Oh and by the way… even though they are called shells they are ACTUALLY probability densities

S orbitals•Each orbital holds 2 electrons

P orbitals•There are 3 suborbitals•Each contains 2 electrons•Total electrons = 6

D orbitals•There are 5 suborbitals•Each contains 2 electrons•Total electrons = 10

F orbitals•There are 7 suborbitals•Each contains 2 electrons•Total electrons = 14

Next class we will learn to fill these orbits with electrons..

Energy levels

n = 3

n = 2

n = 1

n = 4

Energy Levels

The Electron Energy Levels for a Polyeletronic Atom

n = 5

n = 6

n = 7

1s

2s

3s

4s

5s

6s

7s

2p

3p

7p 6d 5f

4f5d6p

5p

3d

4d

4p

Homework: • Hebden: Read p. 151-157 Q’s 26-29 odds