Chemical Compound Naming Rules in Physical Science

Rule
• Compounds with two elements are named using their respective names.
• The Periodic Table's left elements are usually named first.
• The right elements' names are changed by adding "–ide" at the end.

Element Subscripts
• The number subscript indicates the number of atoms in the compound.
• Single atoms do not have subscripts.

Compound Names
• "Mono" means one, "di" means two, "tri" means three, "tetra" means four, and "pent" means five.
• "–ate" or "–ite" is added to compounds containing three elements including oxygen.

Hydroxides
• NaOH = sodium hydroxide, Ca(OH)2 = calcium hydroxide.

Polyatomic Ions
• Groups enclosed in brackets with a numerical subscript indicate more than one polyatomic ion.

Common Names
• NH3 = ammonia, H2O = water, NaCl = sodium chloride = table salt.

Law of Constant Composition
• Compounds always consist of the same ratio of elements.