AP BIOLOGY

Detailed explanation-1: -At 4 °C, the clusters start forming. The molecules are still slowing down and coming closer together, but the formation of clusters makes the molecules be further apart. Cluster formation is the bigger effect, so the density starts to decrease. Thus, the density of water is a maximum at 4 °C.

Detailed explanation-2: -Water’s density is greatest at about 4 °C (39.2 °F), in the liquid phase. Ice, water’s solid phase, is more buoyant, so it forms at the surface of water bodies and freezes downward.

Detailed explanation-3: -Water is densest at 3.98°C and is least dense at 0°C (freezing point). Water density changes with temperature and salinity. When water freezes at 0°C, a rigid open lattice (like a web) of hydrogen-bonded molecules is formed. It is this open structure that makes ice less dense than liquid water.

Detailed explanation-4: -Strangely enough for the liquid state, water is the densest at 4 degrees C, and therefore it stays on the bottom whether it’s in a glass or in an ocean. If you chill water below 4 degrees, it starts to expand again.

Detailed explanation-5: -Answer and Explanation: Water at 4 degrees Celsius is denser than water at 0 degrees Celsius. Water is less dense when it in its solid form as ice.