Atomic Weight: Atomic weight values represent weighted average of the masses of all naturally occurring isotopes of an element. The values shown here are based on the IUPAC Commission determinations (Pure Appl. Chem. 73:667-683, 2001). The elements marked with an asterisk have no stable nuclides. For these elements the weight value shown represents the mass number of the longest-lived isotope of the element.

 

Related Words

Atomic Weight: The sum of the weights of an atoms protons and neutrons, the atomic weight differs between isotopes of the same element.

Molecular Weight: The average mass of a molecule, calculated by summing the atomic weights of atoms in the molecular formula. Note that the words mass and weight are often used interchangeably in chemistry.

Formula Weight: The formula weight is the sum of the atomic weights of the atoms in an empirical formula. Formula weights are usually written in atomic mass units (u).

Swing Weight: The relative weight of a clubhead's leverage (usually measured on a scale with a 12 or 14-inch fulcrum), technically - moment of inertia, or the tendency of a body to resist angular accelera . . . View Full Definition