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