CHEM 0910 CHAPTER 6 PETER BELL SPRING 2017 IONIC AND MOLECULAR COMPOUNDS  Compounds are substances of 2 or more elements combined in a definite proportion  Be able to identify a compound as either ionic or molecular.  Recognize why compounds usually form  octet rule o Stability 
6.1 Ions: Transfer of Electrons  Understand the octet rule and its relationship to ionic compounds  Be able to predict the charge of main group cations and anions o Also know Ag+, Cd2+, and Zn2+ (they follow the pattern discussed!)  Recognize the charge on transition metals given a name or formula of a compound  Know trends in ionic size as discussed in class 6.2 Writing Formulas for Ionic Compounds  Ionic compounds are formed from a metal and a non‐metal. (or polyatomic ion…obviously)  In compounds, the total charge of cations is equal to the total charge of anions 6.3 Naming Ionic Compounds  Name the ions – cation first, anion second  Cations are named the same as the metal o If a transition metal that can have different charges is the cation, indicate the charge with a Roman numeral  Anions are the first syllable of the element with the suffix ‐ide 6.4 Polyatomic Ions 
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Charged molecular species with 2+ atoms connected by covalent bonds Know all the polyatomic ions in table 6.7 There is a pattern for most of them, see Polyatomic Ion handout. If more than one of a particular ion are needed in a chemical formula, the ion is enclosed in parentheses. The subscript then applies to the ion. Ca3(PO4)3 – 2 Ca2+ and 3 PO43– 6.5 Molecular Compounds: Sharing Electrons 
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Covalent compounds are formed between two non‐metals Atoms satisfy octet rule by sharing electrons Know the diatomic elements First element is named the same as the element. Second element is given the suffix ‐ide. Prefixes (know Table 6.12) are given to match the number of each element o “mono” is omitted except in CO 1 CHEM 0910 CHAPTER 6 PETER BELL SPRING 2017 6.6 Electronegativity and Bond Polarity 
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Understand the concept of electronegativity Understand the consequences of differing electronegativity on the way atoms interact Be able to apply the rules of thumb discussed in class to identify polar vs non‐polar bonds Some of this was also covered in lab lecture. 6.7 Shapes and Polarity of Molecules  Be able to predict the electron arrangement and molecular shape about an atom in a molecule based on a Lewis Structure  Know the electron arrangements for two to four electron sets  Know the molecular shapes  Know the bond angles associated with each electron arrangement  Understand how lone pairs affect bond angles  Recognize how polar and non‐polar bonds contribute to the overall polarity of a molecule  This was covered in lab lecture. 6.8 Attractive Forces in Compounds  Rationalize the differences in properties based on different intermolecular forces  Be able to recognize intermolecular forces o dispersion forces o dipole‐dipole interactions o hydrogen bonds o ion‐dipole interactions  The Chemistry Link to Health on Attractive Forces in Biological Compounds is a great look at one of the final topics we will cover this term. Intermolecular forces will be an important theme right up to the final exam and are an key concept in much of the chemistry relevant to biology you will learn and healthcare. 2