The importance of a full outer shell

Part 1

Energy Levels

The orbitals (or shells) of the atom are not just places for the electrons to hang out, they are quantum energy levels within the atom.

An atom achieves the greatest energy stability if the outer shell is full.

Inert gases

• All the inert gases (find these on your PT) have a full outer shell.

• They are very stable and “happy” • They do not react with any other elements.

How atoms get a full outer shell

• None of the other elements have full outer shells – they are “unhappy”

To achieve the “perfect” stable energy state, they can eitherGain electrons to fill the outer shell Lose electrons and shed the outer shell

To gain or lose electrons atoms must interact with each other.

• But first lets have some practice.