ELECTRON CONFIGURATION

Mrs. Nading

Conceptual Chemistry A

What is Electron Configuration?

What do we know about electron configuration now?

- Electron Cloud

- Bohr Model

- Need a more accurate way of diagraming/configuring where electrons go in an atom

The Bohr Model

Spherical Organization Energy Levels Electrons can increase or decrease in

energy by moving from one level to another.

Giving off energy-

Moving down a level Absorbing Energy –

Moving up a level

Orbitals

The Aufbau Principle

Aufbau – German for ‘Filling Up’ Electrons fill order from low to high

energy

Pauli Exclusion Principle

Each Orbital can only contain 2 electrons

They must be facing opposite directions

Hunds Rule

If there is more than one orbital at the same energy level, they fill one by one before pairing.

What are these energy levels you speak of? Remember: Bohr Model, the levels are

represented spherically With Orbitals, the energy levels are

represented in different shapes and sizes

Orbitals have shapes

The S orbital – holds 1 pair of electrons

How we see it

How we write it

P-Orbital – Holds 3 pairs of electons How it looks

How we write it

D-Orbitals – Can hold 5 electron pairs How they look

How we write them

F-Orbitals – Can hold 7 electron pairs How they look

How we write them

How our Energy Levels are arranged

Remember our Periodic Table?

How do we apply this information? Where do we start? Step one – Pick an element Step two – Figure out how many

electrons that element has Step three – draw out or refer to your

aufbau diagram Step 4 - Fill the electron shells

systematically

We need to combine some Info

We need to combine our orbital notation with our Energy level arrangement.

Let’s try it

H S Mn