Definition of Mole and it’s relationship with mass

 Definition of Mole and it’s relationship with mass

 It is an amount of a substance which contains as many particles as there are in

12 g of C-12 isotopes that is  6.022X10²³

6.022X10²³ is known as Avogadro's number.

For example: 1 mole atoms = gram atomic mass = 6.022X10²³ atoms

                 
 1 mole oxygen atoms = gram atomic mass of oxygen =16 g = 6.022X10²³ atoms

1 mole molecules  = gram molecular  mass = 6.022X10²³  molecules

Example -

1 mole oxygen  molecules  = gram molecular  mass of oxygen =32 g =

6.022X10²³ oxygen molecules

1 mole ions  = formula unit mass = 6.022X10²³ ions

Example - 1 mole( SO₄)^2- ions  = formula unit mass of ( SO₄)^2-=96g = 6.022X10²³
  ( SO₄)²ions

The mass (nucleon) number, A, is the sum of the protons and the neutrons. (= 12 for Carbon)

The atomic (proton) number, Z, of an element is the number of protons in the nucleus of the atom. In the neutral atom it is equal to the number of electrons. ( 6 for Carbon)

The Relative Atomic Mass, A(r), is the mass of one atom of an element compared to a scale in which one atom of carbon-12 has a mass of 12.0000.

The Relative Molecular Mass, M(r), is the ratio of the mass of one molecule of a substance to the mass of one atom of carbon-12. It is calculated by adding the relative atomic masses of all the atoms of all elements in the molecule.

Relative molecular mass, M(r), or  relative formula mass (for those compounds that do not exist as molecules) is calculated by adding together the Relative Atomic MassA(r) ‘s of the elements in the molecular formula.