*More than 4 million chemical compounds exist. Nomenclature *More than 4 million chemical compounds exist.

Binary compounds – Composed of 2 elements 1. Metal – Nonmetal 2. 2 Nonmetals

Type I binary compounds – Contain fixed-charged metals 1. Cation (+) written first ; Anion (-) written second 2. Name the cation 3. Name the root of the anion and add “-ide”

Type II binary compounds – Contain variable-charged metals 1. Use roman numerals in parentheses after the metal to signify its charge 2. Name the cation and its charge 3. Name the root of the anion and add “-ide”

Type III compounds – contain only nonmetals 1. The first element in the formula is named first 2. The second element is named as though it were an anion 3. Prefixes are used to denote the number of atoms present 4. The prefix “mono-” is never used for naming the first element.

Prefix # indicated Roman Numeral Mono- 1 I di- 2 II tri- 3 III tetra- 4 IV penta- 5 V hexa- 6 VI hepta- 7 VII octa- 8 VIII

Polyatomic Ions – Charged entities composed of several atoms bonded together. *names must be learned!!

Oxyanions – Contain a given element and different numbers of oxygen atoms -ite = one with the smaller # of oxygen -ate = one with the larger # of oxygen When more than 2 oxyanions Hypo- = less than Per- = more than

Acids – Molecules that produce H+ ions when dissolved in water *formula starts with H 1. If the anion does not contain oxygen: Prefix – “hydro” ; suffix – “ic” attached to root of element or group, then acid 2. When anion contains oxygen: Name is formed from the root name of the central element of the anion or the anion name Suffix: ate = ic ite = ous