What is mole, molecular weight, atomic weight, atomic mass, molecular mass, and how molecules are formed?

Asked by JASKAMAL KAUR | 3rd Dec, 2014, 04:59: PM

Expert Answer:

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Mole: A mole is the amount of pure substance containing the same number of chemical units as there are atoms in exactly 12 grams of carbon-12.

Molecular weight: The molecular weight of a compound is the sum of the atomic weights of the atoms in the molecules that form these compounds.

Atomic weight: It is the average weight of an atom of an element, formerly based on the weight of one hydrogen atom taken as a unit or on 1/16 (0.0625) the weight of an oxygen atom or on 1/12 the weight of the carbon-12 atom.


The atomic weight of an element is the weighted average of the atomic masses of the different isotopes of an element.

Atomic mass: Atomic mass is the mass of a single atom or an individual isotope most often expressed in unified atomic mass units.


Atomic mass is the total mass of protons, neutrons, and electrons in a given element, commonly expressed in unified atomic mass units.


Molecular mass: The molecular mass of a substance is the mass of one molecule of that substance, in unified atomic mass unit(s) (equal to 1/12 the mass of one atom of the isotope carbon-12).


Molecule formation: A molecule is formed when two or more atoms join together chemically. There are three important types of bonds due to which molecules are formed.

Ionic bond, Covalent bond, Hydrogen bond.

Topperlearning Team.

Answered by Arvind Diwale | 3rd Dec, 2014, 06:17: PM

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