1. Periodic Table Set-up

3. Periodic Trends Atomic Radius : 1/2 distance between 2 nuclei of the same element. Group Trend: Increases Why: e-are being added to new energy levels further away, electron shielding occurs, so the nucleus can not pull electrons in a close. Period Trend: Decreases → Why: e-are being added to the same energy level. As the nucleus becomes stronger, the electrons are drawn in closer.

4. Ionization Energy: The energy required to remove an e-. Group Trend: Decrease → Why: e-are further away (shielded) and easier to take away. Period Trend: Increase → Why: e-are closer to nucleus + harder to remove. Atoms are closer to having a complete valence shell and want to gain not lose e-.

5. Electron Affinity : ability to attract e- Group Trend:Decreases Why: Electrons are harder to bring in further away with the nucleus pulling less. Period Trend: Increases → Why: e- are easier to bring in due to a stronger nucleus Atoms want to complete their valence shell. Electronegativity : ability to attract e-in a bond → scale of O-4 F=4.0

6. Ion Size cations (+) : lose valence e' Effect on Radius: decrease due to loss of energy level. anions (+): gain electrons Effect on Radius : l,l, increases due to addition of e- to the same energy level and not changing the strength of the nucleus.