The molecular weight of copper is 63.546 multiplied by the number of atoms present in the sample. Copper is an element rather than a compound, so the correct metric to describe its weight is either its atomic weight or its molar weight.
For any element, the molar weight is closely related to its atomic weight. Copper, which is element number 29 on the periodic table and has 29 protons, has a listed atomic weight of 63.546. This means that a pure sample of copper's most abundant isotope has a molar weight of 63.546 g/mol. Computing the molecular weight of a sample of copper involves multiplying the mass of copper in atomic units by the number of atoms present in the formula.