The density of a substance and its atomic/molecular weight are related through the concept of molar mass.
Molar mass is the mass of one mole of a substance, expressed in grams/mol. It is calculated by summing the atomic/molecular weights of all the atoms/molecules in the substance.
The relationship between density (ρ), molar mass (M), and volume (V) can be described by the following equation:
ρ = M/V
This equation states that the density of a substance is equal to its molar mass divided by its volume.
Since the molar mass is dependent on the atomic/molecular weight of the substance, we can say that there is an indirect relationship between the density and atomic/molecular weight. In general, substances with higher atomic/molecular weights tend to have higher molar masses, which in turn can lead to higher densities.
However, it's important to note that density is not solely determined by atomic/molecular weight. Other factors such as the packing arrangement of atoms/molecules, intermolecular forces, and temperature can also influence the density of a substance.