Which one of the following regarding density of water at atmospheric pressure is correct?

The density of water is highly dependent on temperature due to its anomalous expansion properties. Unlike most substances that contract upon cooling, water reaches its maximum density at approximately 4°C (specifically 3.98°C). At this temperature, the density of pure water at standard atmospheric pressure is approximately 1000 kg/m³ (or 1 g/cm³) [1]. As water cools from 4°C down to 0°C, it begins to expand rather than contract, causing its density to decrease. This occurs because hydrogen bonds begin to form a more open, structured hexagonal lattice as it approaches the freezing point [1]. Consequently, ice at 0°C is less dense than liquid water at 4°C, which is why ice floats. Therefore, the statement that the density of water at 4°C is 1000 kg/m³ is scientifically accurate.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > 2.3. The Sun > p. 23