1. How to Write Chemical Formulas Ionic Compounds Next  End

2. Types of Chemical Compounds Chemical compounds can be classified into two basic categories, binary and ternary. Binary compounds contain two different elements. Ternary compounds contain three or more different elements. In order to distinguish between binary and ternary you must determine if a polyatomic ion is present. Most polyatomic ions end in “ate” or “ite”, with a few exceptions, hydroxide, cyanide, and ammonium. Both types of compounds can contain transition metals which are indicated by a roman numeral in the name. Next  End

3. Steps to writing formulas Most chemical compounds have two names. The first name is the positive ion (cation) and the second name is the negative ion (anion). In a binary compound, the first name will be a metal ion. The second name will be a nonmetal ion.binary compound In a ternary compound, the first name will be a metal ion with the exception of ammonium. The second name will almost always be a polyatomic ion.ternary compound –Click on “binary compound” or “ternary compound” to see their definitions; select “Binary” or “Ternary” below to practice writing their formulas BinaryTernary End

4. Binary Ionic Compounds Sodium Chloride Step 1: Write the symbols for the metal and nonmetal ions. The metal always goes first. »Na Cl Step 2: Determine the charge for each ion and write it as a superscript. »Na +1 Cl -1 Step 3: “Crisscross” the charges and remove the sign to become the subscripts of the chemical formula. If the numbers are the same, they cancel each other out. »NaCl Back to Writing FormulasAnother Example End

5. Binary Ionic Compounds Magnesium Nitride Step 1: Write Symbols »Mg N Step 2: Determine charges »Mg +2 N -3 Step 3: Crisscross charges to become subscripts »Mg 3 N 2 Back to Writing FormulasBinary w/Transition Metals End

6. Ternary Ionic Compounds Barium Phosphate Step 1: Write the symbols for the two ions. The positive ion always goes first. »Ba PO 4 Step 2: Determine the charge for each ion and write it as a superscript. »Ba +2 PO 4 -3 Step 3: “Crisscross” the charges and remove the sign to become the subscripts of the chemical formula. If the numbers are the same, they cancel each other out. »Ba 3 (PO 4 ) 2 Back to Writing FormulasAnother Example End

7. Ternary Ionic Compounds Ammonium Carbonate Step 1: Write Symbols »NH 4 CO 3 Step 2: Determine charges »NH 4 +1 CO 3 -2 Step 3: Crisscross charges to become subscripts »(NH 4 ) 2 CO 3 Back to Writing FormulasTernary w/Transition Metals End

8. Compounds with Transition Metals (Binary) Iron II Sulfide Step 1: Write Symbols »Fe S Step 2: Determine charges (roman numeral gives the charge) »Fe +2 S -2 Step 3:Crisscross charges to become subscripts »FeS Back to Writing Formulas End

9. Compounds with Transition Metals (Ternary) Manganese IV Nitrate Step 1: Write Symbols »Mn NO 3 Step 2: Determine charges (roman numeral gives the charge) »Mn +4 NO 3 +1 Step 3:Crisscross charges to become subscripts »Mn(NO 3 ) 4 Back to Writing Formulas End

10. How to Write Chemical Formulas Next Lesson: Molecular Compounds