Module 4: Bonding, Formula Writing, and Nomenclature

Student in WheelchairIn this module, you learned about the ways chemical bonds form, how compounds are named, and the forces that hold bonds together. Throughout this investigation, you have learned that chemical bonds hold groups of atoms together to form molecular and ionic substances. Bonds which are ionic contain ions in which an electron, or electrons, are transferred from one atom to another. When naming ionic compounds, the metal is named first, followed by the name of the nonmetal with an “-ide” ending. Molecular substances contain covalent bonds in which electrons are shared. Molecular compounds are named by using prefixes such as "mono-", "di-" and "tri-" to indicate the number of atoms. Compounds share or transfer electrons in order to obtain a stable electron configuration. Lewis dot structures represent the electron arrangement of atoms in a compound and can be used to help predict the structure of a compound using the Valence Shell Electron Pair Repulsion theory (VSEPR). The shape of a molecule is used to determine whether it is polar or nonpolar. Polar molecules are held together through dipole forces and the much smaller London dispersion forces. Finally, the only intermolecular forces holding nonpolar molecules together as a solid or liquid are London dispersion forces.