Question
Wed February 01, 2012 By: Shaik Mohammed Ali

wat is a valency,atomic mass no. &explain avagadro's no.

Expert Reply
Thu February 02, 2012

Valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element.

 Atomic Number:-The number of protons present in the nucleus is equal to atomic number (Z)

 Mass Number: - The total number of protons (Z) and neutrons (n) is equal to mass number (A) of the atom.

Mass number (A) = Number of protons (Z) + Number of neutrons (n)

Avogadro’s number is equal to the number of particles or entities present in one mole of a substance.

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