Lewis Structures

Here are the videos of this concept being taught to a Year 12 class:

So that is what we are expected to remember from last year. This year, things get a little more difficult; we need to know how to draw Lewis Structures which do not obey the Octet Rule and for polyatomic ions:

BEHOLD!!!

A must see use of scientific resources for fun.

World's Smallest Stop-motion movie

Ionisation Energy

We need to know a fair bit about Ionisation Energy:

1. Define 1st I.E.
2. Justify the trend in 1st I.E. down a Group
3. Justify the trend in 1st I.E. across a Period
4. Use consecutive I.E. values to infer electron configuration/number of valence electrons.

Periodic Table Trends: Ionization Energy: What an ion is. Using the periodic table to understand how difficult it is to ionize an atom.

Electronegativity

Electronegativity generally increases across a Period and generally decreases down a Group. We need to be able to justify these trends this year:

Atomic and Ionic Radius

Atomic Radius

As you move down a group, the outermost electrons are in a higher energy level, so subject to more electric shielding. Therefore, atomic radius increases down a group.

As you move across a period, the number of protons in the nucleus increases, yet the number of energy levels stays the same. Therefore, there is more effective charge on each of the outermost electrons, so the radius decreases. As we are adding more electrons to the same orbital, you would expect there to be an increase in electric repulsion between the electrons. This is true but has negligible effect compared to the increase in nuclear charge.

Ionic Radius

Electron Configurations Video