A The liter of water will be equivalent to 1,000 milliliters of water. Each of those milliliters is equivalent to one cubic centimeter, so the liter of water is equivalent to 1,000 cubic centimeters. Density is defined as the mass divided by the volume. Even if you forget that, you are asked for the density "in grams per cubic centimeter." This means that the 1,000 grams get divided by the 1,000 cubic centimeters, which equals 1 .