Chemical nomenclature

Chemical nomenclature refers to the system of naming particles ranging from individual atoms to complex molecules. There are a few rules to know to name chemicals at a high school level.

Molecular compounds
Molecular compounds are identified by being composed of non-metals. Naming a molecular compound is as follows:
 * 1) The more electropositive element (farther to the left on the periodic table) is listed first, and any Greek prefixes denoting quantity applied
 * 2) The less electropositive element follows, along with any Greek prefixes denoting quantity
 * 3) Replace the ending of the second element with -ide (chlorine becomes chloride, fluorine becomes fluoride, oxygen becomes oxide)

Ionic compounds
Ionic compounds are identified by being composed of at least one metal and one non-metal. The primary difference between molecular and ionic compounds is that the first element does not have Greek prefixes applied to it. The steps to naming ionic compounds are as follows:
 * 1) The cation is listed first, it can be a metal or a polyatomic ion
 * 2) The anion follows, along with any Greek prefixes denoting quantity
 * 3) Replace the ending of the anion with -ide

Multivalency
Some metals, particularly the transition metals, can take on various electron configurations in their valence shell, making different compounds possible with the same two elements. There is no rule for determining the possible valence shells, so they must be memorized.

The formal way of naming multivalent compounds is to state the element involved, followed by the Roman numeral for its oxidation state. For example, copper with two electrons is written as Copper(II). The antiquated method of naming them assigns the suffixes -ous and -ic to the original Latin names of the element for the lowest and highest oxidation states, respectively. Copper with two electrons would be written like so:

Cupr (Latin: cupro) + -ic = cupric

Acids
Simple acids, or binary acids, are named by affixing the prefix hydro- and the suffix -ic to the non-hydrogen element and following it with the word 'acid'. For the example of H2S, naming is as follows:

hydro + sulfur + ic acid

There exist polyatomic ions without oxygen in them (e.g. cyanide), and the same rules apply.

Oxyacids
An acid where the anion is a polyatomic ion containing oxygen is called an oxyacid. Oxoacid nomenclature is usually the most difficult aspect of naming compounds. The rules are as follows:
 * 1) Identify the variation of the polyatomic ion ending in -ate (sulfate, chlorate, bromate, etc)
 * 2) Compare the amount of oxygens in that ion to the number of oxygens within the acid
 * 3) Apply the naming conventions bolded below