1/6/09

Post date: Jan 06, 2009 2:4:40 AM

Bell Activity: Where have you seen Roman numerals used? List the first 10 Roman numerals.

    • Roman Numerals

      • 1 = I

      • 2 = II

      • 3 = III

      • 4 = IV

      • 5 = V

      • 6 = VI

      • 7 = VII

      • 8 = VIII

      • 9 = IX

      • 10 = X

    • Some elements (transition metals) form more than one type of cation

      • With these elements, we must include some way to show which ion we're talking about

      • We do this with roman numerals to show the charge of the ion

        • Example: Iron, Fe

          • Iron can give up either 2 or 3 electrons, so it will have either a 2+ or 3+ charge

          • The Iron ion with a 2+ charge is written as Iron (II) ion

          • The Iron ion with a 3+ charge is written as Iron (III) ion

      • Below are the possible charges of the transition metals

    • Writing formulas for ionic compounds

      • Start with a cation and an anion

      • Write the symbols (with charges) for each ion

      • Put them next to each other, with the cation first

      • Cross the charges and bring them down to subscript to show how many of each ion is involved

      • Example: Hydrogen Chloride

      • Example: Iron (III) oxide

  • Naming ionic compounds assignment

      • Given the following compound names, write the formula of each ionic compound

        1. Sodium chloride

        2. Hydrogen fluoride

        3. Copper (II) oxide

        4. Potassium bromide

        5. Magnesium phosphide

    • Naming ionic compounds

      • compounds consist of an anion and a cation

      • Write the name of the anion and the cation

      • Put the two together, with the cation's name first

      • If the cation is a transition metal

        • Find the charge on that transition metal by reversing the cross you did in the last step. If there is one of each type of ion in the compound, the transition metal has the same number (but opposite sign) as the anion.

        • Use roman numerals to indicate which charge that cation has

  • Naming ionic compounds assignment

      • Given the following formulas, write the name of each ionic compound

        1. LiCl

        2. BeF2

        3. Ca2C

        4. HBr

        5. Fe2O3