Final answer:
The density of water at 4°C is approximately 1.0 g/cm³. At this temperature, water reaches its maximum density before it starts to decrease. This is why ice forms at the top of a body of water.
Step-by-step explanation:
The density of water at 4°C is approximately 1.0 g/cm³. At this temperature, water reaches its maximum density before it starts to decrease. This is why ice forms at the top of a body of water. The decrease in density below 4°C occurs because the liquid water approaches the solid crystal form of ice, which contains more empty space than the liquid.