Question

Name the behaviour of water between its temperature from 0°C to 4°C.

Hint:

The anomalous expansion of water is crucial for life on Earth because it allows ice to float on water, insulating aquatic life during freezing temperatures.

Answer 1

Water exhibits an anomalous expansion between 0$^{\circ}$C and 4$^{\circ}$C. Normally, most substances expand when heated and contract when cooled. However, water behaves differently in this specific temperature range. When water at 0$^{\circ}$C is heated, instead of expanding, it contracts until its temperature reaches 4$^{\circ}$C. Above 4$^{\circ}$C, it begins to expand like other substances. This means water has its maximum density at 4$^{\circ}$C. The reasons for this anomaly are due to the unique hydrogen bonds in water. At temperatures below 4$^{\circ}$C, the water molecules arrange themselves in a more open hexagonal structure due to hydrogen bonding, which increases the volume and decreases the density of the water.