grams g are a metric unit used for measuring mass
mass_unit is not unit_of_measurement. gram is metric_weight_unit. mass_number is mass_unit. unit_of_mass is unit_of_measure. gram is not metric_weight_unit. gram_molecule is metric_weight_unit. metric_weight_unit is mass_unit. metric_weight_unit is not mass_unit. mass_unit is unit_of_measurement. gram_molecule is not metric_weight_unit.