Unit #1Unit #2Unit #3Unit #4Unit #5Unit #6Unit #7Unit #8Unit #9Unit #10
spacerUNIT # 5  
spacerspacerIntroduction
spacerspacerObjectives
spacerspacerReading


spacer5.1 Ionic
spacerBonding

spacerIonic Bonding in Sodium Chloride
spacerIonic Bonding in Magnesium Chloride
spacerProperties of Ionic Compounds
spacer5.2 Covalent
spacerBonding
spacer5.3 Polar Covalent
spacerBonding

spacer5.4 Bond
spacerDipoles

spacer5.5 Electroneg-
spacerativity

spacer5.6 Classification
spacerof Bond Type
spacer5.7 Polarity of
spacerMolecules
spacer5.8 Writing
spacerChemical
spacerFormulae
spacerWriting formulas containing simple ions
spacerWriting formulas containing  polyatomic ions
spacerUsing parentheses in formula writing
spacer5.9 Information in
spacera Chemical
spacerFormula
spacerNumber ratio of atoms
spacerNumber ratio of ions
spacer5.10 Oxidation
spacerNumbers
spacerAssignment of Oxidation Numbers


spacerspacerProblems
spacer1 | 2
Unit #5 COMPOUNDS

5.8 -
Writing Chemical Formulae

All compounds are electrically neutral.

Remember these three points:

  1. In section 4.9.1, we learned that metals tend to lose their valence electrons to form cations.
  2. In section 4.9.2, we learned that nonmetals tend to gain electrons to form anions.
  3. In section 4.5, we learned that when an ion is formed, the number of electrons that is gained or lost is determined by the octet rule.

Click here to review the charge of ions that representative elements tend to form.

Follow these simple steps to write chemical formulas for ionic compounds. The steps are the same whether the compound contains simple ions of Group A elements or polyatomic ions.
(section 5.8.1)
(section 5.8.2)


Click onChemist's Tooland find the icon to learn the names, formulas and charges from the list of polyatomic ions for this course.


Section 6.9
Writing Formulas ..p147


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