Platinum has a density of 21 g/cm3. A platinum ring is placed in a graduated cylinder that contains water. The water level rises from 7.0 mL to 7.4 mL when the ring is added. What is the mass of the ring?
take the difference of water levels to find volume of the ring. convert ml to cm3. multiply by density to cancel out cm3 units (idk how to explain that well). you get 8.4g