1. Electron Configuration and Periodic Properties

2. Atomic Radii
One-half the distance between the nuclei of identical atoms that are bonded together.

3. Ionization Energy
The energy required to remove one electron from a neutral atom of an element.

4. Electron Affinity
The energy change that occurs when an electron is acquired by a neutral atom.

5. Ionic Radii Cation- Positive ion Anion- Negative ion
Cations are smaller
and anions are larger
than the atoms from
which they are
formed.

6. Number of valence electrons
Electrons available to be lost, gained, or shared in the formation of chemical compounds.
Group number
Group configuration
Number of valence electrons 1
ns1 2
ns2 13
ns2p1 3 14
ns2p2 4 15
ns2p3 5 16
ns2p4 6 17
ns2p5 7 18
ns2p6 8

7. Electronegativity
Measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound.

8. E= 2s22p4
G= 4d105s25p4
J= 2s22p1
L= 5d106s26p4
M= 2s22p3

9. Identify the block for each element.
Determine which elements are in same period/ same group.
Which element has highest electron affinity?
Which would form a -1 ion?
Which has highest electronegativity?
Compare the ionic radius of ion formed by G with radius of neutral atom of G.
How many valence electrons are in each element?