1. Atomic Radius
The atomic radius of a chemical element is a measure of the:
Distance from the nucleus to the boundary of the surrounding cloud of electrons.

2. Atomic Radii

3. Ionization Energy
Ion- atom or group of bonded atoms that has a positive or negative charge.
Ionization-any process that gives an ion.
Ionization energy-energy required to remove one electron from a neutral atom of an element

5. Electron Affinity
Electron Affinity- the energy change that occurs when an electron is acquired by a neutral atom
Sometimes atoms gain electrons easily and sometimes they are forced to gain them by adding energy
Groups 2, 12, 18- ZERO AFFINITY
Full valence electron shell

7. Ionic Radius The radius of an atom’s ion
Ion=Different Number of Electrons
Trend: Down to Francium (Fr) and to the right (Halogens) Outer Edges are bigger than the middle

9. Valence Electrons
Valence Electron: the electron(s) that are able to be gained, lost, or shared with another atom to make a bond
Valence: outside; perimeter; edge
Main Group Elements…We will not do transition metals at this time. 

10. VE=Valence Electron Group 1: 1 VE Group 2: 2 VE Group 13 (3): 3 VE
For Groups (main group) just take off the one of the group number to get the VE number.
Group 18 has full Valence shell
He is being the bad brother with a full shell with 2 e-

11. Electronegativity
Def: is a measure of the tendency of an atom to attract a bonding pair of electrons.
The Pauling scale is the most commonly used.
Fluorine (the most electronegative element) is assigned a value of 4.0.
Caesium and Francium which are the least electronegative are assigned a value at 0.7.
Trend: Increases up the chart and to the right