CBSE Class 11-science Answered

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.

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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.

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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.