The density of water is 1 gram per cubic centimeter. A more dense object will sink, and a less dense object will float. Will a marble with a radius of 1.4 cm and a mass of 9 grams sink or float in water? The marble will (float/sink) because the density of the marble is about (0.71, 0.78, 1.28, 1.40) grams per cubic centimeter.