Which of the following relation is

Solution

The number of atoms of ANY substance in a volume is: # of atoms = N × (density) × volume / (Molecular Weight). N is a constant called Avogadro's number and its equal to 6.022×10²³ atoms/mole. It can also be molecules per mole. Avogadro's number is a proportion that relates molar mass on an atomic scale to physical mass on a human scale. Avogadro's number is defined as the number of elementary particles (molecules, atoms, compounds, etc.) per mole of a substance. It is equal to 6.022 × 10²³ mol^-1 and is expressed as the symbol NA.