Chemical Periodicity

Atomic Size•Size increases as you go down in any column

•Size decreases from left to right in any row

Ionic Size•Size increases as total charge decreases

•C+2 > C+4

•F-1 > F

Rank the elements from their atomic number

from smallest to largest

9, 55, 13, 11, & 1

Ionization Energy•The energy required to remove electrons from atoms or ions

1st Ionization Energy• Decreases as you go

down any column

• Increases from left to right on any row

• Fr <<<<<<<<<<<<<He

Shielding Effect• The further away an

electron is from the nucleus, the more electron clouds lie between the electron & the nucleus

Drill:• Arrange the following atoms

from lowest to highest 1st ionization energies:

• 2, 20, 14, 55, 7

Review HW•Problems:

•40 – 42 & 57 – 64

•on pages 170 & 171

Ionization Energies

•2nd > 1st

•3rd > 2nd

•Massive increase when a shell is emptied

Electron Affinity•The attraction of electrons by an atom

Electron Affinity• Decreases as you go

down any column

• Increases from left to right across any row

• Fr <<<<<<<<<<<< F

Electronegativity

•The attraction of shared pairs of

electrons by an atom

Electronegativity• Decreases as you go

down any column

• Increases from left to right across any row

• Fr <<<<<<<<<<<< F

Metallic Character

•Increases as you go down any column

•Decreases from left to right across any row

Reactivity•Metals 1A > 2A > 3A

•Metals increase down

•Nonmetals increase as you get closer to F

Metal Oxides•When dissolved in water, make basic solutions

•Sometimes called basic anhydrides

•MgO, Na2O, etc

Non-metal Oxides•When dissolved in water, make acidic solutions

•Sometimes called acid anhydrides

•CO2, SO2, SO3, NO2

Metal Hydrides•Metals bonded to H

•When dissolved in water, make basic solutions

•NaH, MgH2, AlH3, etc

Non-metal Hydrides•Non-metals bonded to H

•When dissolved in water, make acidic solutions

•HCl, H2S, HBr, etc

•Exception: NH3

Place the following elements in largest to smallest order

with respect to: 1) diameter 2) 1st ionization energy

3) electronegativity 4) metalic character

• Elements #: 1,5, 8, 15, 56

Identify as ionic, covalent, or metallic bonds

Na-Cl Fe-CrS-Cl H-Cl

Mg-S C-CN-O Fe-Fe