Answer:
At the same temperature of 0°C, the density (mass per volume) of ice is 0.9187 gram per cubic centimeter (g cm-3 or g/cm3) while that of liquid water is 0.9998 g cm-3 (Cohen et al. 2003). The lesser density means that ice contains lesser mass (quantity of matter) per unit of volume. It also means that the molecules of water are less compressed per unit volume of ice. Another way of saying it is that ice is less compact than liquid water having the same volume.