The gram atomic mass of an element is equal to Avogadro's number, which is approximately 6.023 × 10^23 atoms/mol. This relationship arises from the concept of molar mass and Avogadro's law.
Avogadro's number, denoted as "Nₐ," represents the number of entities (atoms, molecules, or ions) in one mole of a substance. It is a fundamental constant in chemistry and is defined as exactly 6.02214076 × 10^23 entities/mol.
When we calculate the molar mass of an element, we are essentially determining the mass of one mole of atoms of that element. The molar mass is expressed in grams per mole (g/mol). Therefore, if we weigh an amount of substance equal to its molar mass in grams, we will have precisely one mole of that substance, containing Avogadro's number of atoms.
Hence, the gram atomic mass of an element is equal to Avogadro's number because it is based on the concept of molar mass and the relationship between mass and the number of atoms in a mole of a substance.