2007-01-11 15:49:03 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Something is an atom if it is made of one single element. Generally speaking, molecules are made of atoms that are covalently bonded (ususally two or more nonmetallic elements) and formula units are made of atoms that bond ionically (if that is a word - anyway that usually happens when a metallic element bonds with a nonmetallic element.) Molecules exist as a single unit, but a formula unit represents the lowest ratio of ions that are found in a crystalline structure. (Meaning NaCl doesn't exist as individual particles of NaCl. It is a formula unit representing the ratio of Na:Cl within all NaCl crystals.) Hope that helped.
2007-01-11 16:16:22 · answer #1 · answered by Lori 2 · 0⤊ 0⤋
A chemical formula, such as H2O (water) refers to a molecule. The components of the expression (H and O in this case) refere to atoms of specified elements. Hydrogen and Oxygen are two different elements that combine in a two to one ratio to make water.
2007-01-11 15:56:26 · answer #2 · answered by Richard B 4 · 0⤊ 0⤋