To communicate clearly, chemists use a standardized system for naming chemical compounds called the IUPAC (International Union of Pure and Applied Chemistry) nomenclature. This ensures that every compound has a unique name that reveals its chemical composition.

Naming Monatomic Ions

Monatomic cations (positive ions) are named by using the element’s name. Monatomic anions (negative ions) are named by dropping the end of the element’s name and adding the suffix “–ide.”

Naming Polyatomic Ions

Ions containing more than one type of atom are polyatomic ions. When writing the symbol/formula of a polyatomic ion, the symbol of the cation is written first, followed by the symbol of the anion. The overall charge of a polyatomic ion is the sum of the individual oxidation numbers for each atom in that ion .

Polyatomic cations formed from nonmetal atoms have names that end in “–ium.”
Polyatomic anions may be written in different ways depending on the number of atoms and the elements that combine. For example, some are named in the same way as monatomic ions with “–ide” at the end of the name (as a suffix).
Polyatomic anions that contain oxygen have names that end in “–ate” or “–ite.” These anions are known as oxyanions.
An ion that contains hydrogen and an oxyanion is named by adding the word hydrogen or dihydrogen at the beginning of the name (as a prefix).

Ionic compounds are formed from oppositely charged ions bonded together by electrical forces. When writing the name or symbol/formula of an ionic compound, the name or symbol/formula of the cation is written first, followed by the name or symbol/formula of the anion.

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Lesson 7: Chemical Formulas and Bonding

1. Lewis Symbols

2. Practice: Valence Electrons

3. Drawing Lewis Structures

4. The Octet Rule

5. Writing Chemical Formulas

6. Naming Chemical Compounds

7. Naming Acids

8. Naming Molecular Compounds

9. Intramolecular Forces

10. Types of Chemical Bonds

10a. Ionic Bonding

10b. Covalent Bonding

10c. Metallic Bonding & Bonding Summary

11. Lewis Structures: Gaining & Losing Electrons

12. Covalent Compounds

13. Ionic Compounds