1.3 Elemental Composition of Pure Substances

Flashcards covering key vocabulary related to the elemental composition of pure substances.

Empirical Formula

The chemical formula that lists the lowest whole number ratio of atoms of the elements in a compound.

Law of Definite Proportions

The principle stating that the ratio of the masses of the constituent elements in any pure sample of a compound is always the same.

Percent Composition

The percent by mass of each element that makes up a compound.

Molecular Formula

The actual formula for a substance, indicating the number of each type of atom present in a molecule.

Formula Unit

The simplest ratio of the ions in an ionic compound.

Molar Mass

The mass of one mole of a substance, usually expressed in grams per mole (g/mol).

Ion

An atom or group of atoms with a charge.

Molecule

A group of nonmetals bonded together, representing the smallest unit of a chemical compound.

Compound

A substance made from two or more different elements that are chemically bonded.

Percent to grams conversion

Assume a 100g sample to change percent composition to grams for calculation purposes.