At what temperature does water reach its maximum density?

Water reaches its maximum density at 4 degrees Celsius. This phenomenon is due to the unique molecular structure of water and how it behaves as it cools and freezes. As water is cooled, the molecules move closer together, increasing density until it reaches 4 degrees Celsius. Below this temperature, the molecules start to form a more stable structure, leading to the formation of ice, which is less dense than liquid water. This characteristic causes ice to float on water, a critical aspect for aquatic life during winter when lakes and ponds freeze from the top down. The other temperature options do not represent the point of maximum density for water, as at 0 degrees Celsius water begins to freeze, and at 100 degrees Celsius it transitions to a gas, which has much lower density. Temperature values below the freezing point, such as -4 degrees Celsius, also do not apply here, as the water is then in a solid state.