3.1: Ions Ions can be positively charged or negatively charged. A Lewis diagram is used to show how electrons are transferred to make ions and ionic compounds. 3.2: Two Types of Bonding Atoms have a tendency to have eight electrons in their valence shell. The attraction of oppositely charged ions is what makes ionic bonds. 3.3: Formulas for Ionic Compounds Proper chemical formulas for ionic compounds balance the total positive charge with the total negative charge. Groups of atoms with an overall charge, called polyatomic ions, also exist. 3.4: Ionic Compounds- Formulas and Names Chemists use nomenclature rules to clearly name compounds. Ionic and molecular compounds are named using somewhat-different methods. Binary ionic compounds typically consist of a metal and a nonmetal. The name of the metal is written first, followed by the name of the nonmetal with its ending changed to –ide. For example, K2O is called potassium oxide. If the metal can form ions with different charges, a Roman numeral in parentheses follows the name of the metal to specify its charge. 3.5: Covalent Bonds You have already seen examples of substances that contain covalent bonds. One substance mentioned previously was water (H₂O). You can tell from its formula that it is not an ionic compound; it is not composed of a metal and a nonmetal. Consequently, its properties are different from those of ionic compounds. A covalent bond is formed between two atoms by sharing electrons. 3.6: Covalent Compounds - Formulas and Names The chemical formula of a simple covalent compound can be determined from its name. The name of a simple covalent compound can be determined from its chemical formula. 3.7: Multiple Covalent Bonds Some molecules must have multiple covalent bonds between atoms to satisfy the octet rule. 3.8: Characteristics of Covalent Bonds Covalent bonds between different atoms have different bond lengths. Covalent bonds can be polar or nonpolar, depending on the electronegativity difference between the atoms involved. 3.9: Characteristics of Molecules A molecule has a certain mass, called the molecular mass. Simple molecules have geometries that can be determined from VSEPR theory. 3.E: Covalent Bonding and Simple Molecular Compounds (Exercises) These are homework exercises to accompany Chapter 4 of the Ball et al. "The Basics of GOB Chemistry" Textmap. 3.E: Ionic Bonding and Simple Ionic Compounds (Exercises) These are homework exercises to accompany Chapter 3 of the Ball et al. "The Basics of GOB Chemistry" Textmap. 3.S: Covalent Bonding and Simple Molecular Compounds (Summary) To ensure that you understand the material in this chapter, you should review the meanings of the following bold terms in the following summary and ask yourself how they relate to the topics in the chapter. 3.S: Ionic Bonding and Simple Ionic Compounds (Summary) To ensure that you understand the material in this chapter, you should review the meanings of the following bold terms and ask yourself how they relate to the topics in the chapter.