Electron Configurations

The Bohr Model was useful in explaining the properties of the first 20 elements but falls down beyond Calcium. To understand the properties of the transition metals and other elements up to Krypton (36), we need to understand s, p and d orbitals.

• s orbitals can hold up to two electrons
• p orbitals can hold up to six electrons in 3 sub-orbitals
• d orbitals can hold up to ten electrons in 5 sub-orbitals

The next thing to get our heads around is how to write the electron configurations for ions. We came up with the "penguin" theory (thanks Bronwyn!!). The penguins on the edge of the ice-pack get taken away by the seals first... The electrons farthest from the nucleus are removed first when cations are formed.

For homework, we have to write the electron configurations for:

1. copper (II)
2. iron (II)
3. iron (III)
4. zinc

We also have to infer why zinc ions form colourless/white compounds.