Chemical Formulas Mrs. Lee Chemical Formulas Mrs. Lee

Significance of a Chemical Formula Gives valuable information about the compound Indicates the relative numbers of atoms of each kind of element present in a compound

Monatomic Ions Ions formed from a single atom are known as monatomic ions Monatomic cations are identified by the elements name Monatomic anions are identified by dropping the ending of the element name and adding “ide” to the end of the name.

Binary Ionic Compounds Compounds composed of two or more elements are binary molecular compounds The total number of positive and negative charges must be equal Crossing over is used to balance the charges between ions in a compound Use absolute values when crossing over

Naming Binary Ionic Compounds Combine the names of the compound’s positive and negative charges The name of the cation is always given first, followed by the anion

Quick Check UP Use whiteboards to answer the practice problems on page 223 of your text book.

Naming Monatomic Ions Some elements have the ability to form more than one ion These ions are identified with roman numerals

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Compounds Containing Polyatomic Ions Oxyanions are polyatomic ions that contain oxygen Some elements combine with oxygen to form mire than one type of anion The name depends on the number of oxygen atoms in the oxyanion

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Binary Molecular Compounds Compounds composed of covalently bonded units or molecules One of the systems for naming these compounds is based on the use of prefixes

Binary Molecular Compounds Compounds between two metals First element in the formula is named first Keeps it’s element name Apply a prefix if the element has a subscript Second element is named second Always use a prefix with the second element

Quick Check UP Use whiteboards to answer the practice problems on page 229 of your text book.

Binary Molecular Compounds

Significance of a Chemical Formula