Terminology

[jonathan chi 1J]

What is the difference between an atom and a formula unit?

[Terrence Chi]

Atom is the basic unit of a chemical element compared to formula unit which is the chemical formula (empirical formula) to show ratios of atoms.

[Emily Chen 1G]

I believe a formula unit refers to a unit of an ionic compound, such as NaCl, while atoms refer to a unit of a single element such as hydrogen. (since molecules are similar I thought I might just throw in that molecules are a unit of covalently bonded elements, such as H2O)

[Matthew Vu 3C]

A formula unit describes the whole ionic compound (for example, the formula unit for sodium chloride would be NaCl), whereas an atom would be just the basic element—the atoms of Nacl would be Na and Cl (sodium and chlorine).

[SarahOMalley1D]

A formula unit is one unit of an ionic compound. An ionic compound is a metal ion and nonmetal ion bonded together. Because of this, formula units will display ionic compounds with subscripts in the simplest forms possible (e.g. NaCl for sodium chloride, not Na2Cl2). On the other hand, an atom is the basic unit of an element. Atoms are electrically neutral, unlike the ions that make up ionic compounds.

[Hannah Carsey 1B]

An atom is the smallest unit of ordinary matter that forms a chemical element. A formula unit in chemistry is the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound.

[Kimia Rategh 2A]

An atom is the smallest unit of matter. Formula units is in relation to a unit (or amount) of ionic compound. A compound is made up of atoms. Though they do not mean the same thing, you can find the number of atoms in a given set of formula units using moles and Avogadro's constant.