7 131-2011su 6-14
DESCRIPTION
June 14 2011 CHM 131 formulas for compoundsTRANSCRIPT
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VALENCE ELECTRONS
• Outer shell e- are involved in “bonding”
• Gain/lose/share
• # e- in atom =
• e- seem to be arranged in energy levels
• Highest energy level electrons
• Largest distance from + nucleus
• “A” group number = # valence electrons
• (“A” groups are “main” group elements)
FORMULAS FOR BINARY SALTS
• Ionic bonding
• Cation – Metals lose e- fairly easily
• Anions – Nonmetals attract e-
Pg 35-39
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CHARGE OF IONS
MAIN GROUP ELEMENTS
• Positive charge = + group number
• Negative charge = group # - 8
FORMULAS FOR COMPOUNDS
• Metal + Nonmetal
• Metal loses e- to non-metal
Na Cl
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HANDOUT PRACTICE
Name Cation Anion formula
Sodium bromide
Calcium iodide
Barium oxide
Aluminum chloride
Lithium nitride
Magnesium sulfide
Strontium fluoride
OTHER METALS
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• Iron (III) chloride
• Lead (IV) sulfide
• Lead (II) sulfide
• Cr2O3
• MnO2
All metals except Group IA, IIA, Al, Ag, Zn, Cd should
use RN in their names – these can all have variable
“oxidation” numbers (charges)
POLYATOMIC ION
• Note root/suffixes
• Group has the charge
• Covalent bonding within group
• Overall extra electrons or too few electrons
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• Sodium sulfate
• Calcium bicarbonate
• Ammonium phosphate
• Manganese (IV) oxide
• FeSO4 Fe2(SO4)3
• Sodium oxalate
Pg 137 – common compounds
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Homework – answers will be on bb
– but Please do the worksheet
before looking at the answers
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REVIEW NAMING