molecular weight

weight of a molecule

The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). This is distinct from the relative molecular mass of a molecule, which is the ratio of the mass of that molecule to 1/12 of the mass of carbon 12 and is a dimensionless number. Relative molecular mass is abbreviated to Mr.
See more at Wikipedia.org...

Noun
1. (chemistry) the sum of the relative atomic masses of the constituent atoms of a molecule
(synonym) relative molecular mass
(hypernym) mass
(classification) chemistry, chemical science

Compare with formula weight and molecular formula .The average mass of a molecule, calculated by summing the atomic weights of atoms in the molecular formula .

n. น้ำหนักโมเลกุล (syn. weight)