ABSTRACT
As we discussed in Chapter 1 (Section 1.4.2), all of the over 13 million chemical compounds that exist consist of elements in chemical combination. Compounds that are “covalent” or “molecular” have molecules as their fundamental particles. Compounds that are “ionic” have formula units as their fundamental particles. Molecules are composed of various numbers of different atoms in covalent chemical combination; formula units are composed of various numbers of different ions.
