Why does ice expands

Why does liquid water have a density maximum? Most liquids have a quite simple behavior when they are cooled at a fixed pressure : they shrink. The liquid contracts as it is cooled; because the molecules are moving slower they are less able to overcome the attractive intermolecular forces drawing them closer to each other. Then the freezing temperature is reached, and the substance solidifies, which causes it to contract some more because crystalline solids are usually tightly packed.

The crystalline arrangement is less dense than that of the molecules in liquid form which makes the ice less dense than the liquid water. When water molecules are in the liquid state, hydrogen bonds are continuously being formed and reformed in a disordered fashion.

During freezing, water molecules lose energy and do not vibrate or move around as vigorously. This allows more stable hydrogen-bonds to form between water molecules, as there is less energy to break the bonds.

No, it is not. Other such substances include plutonium, germanium, bismuth, gallium, silicon, acetic acid, etc. This phenomenon, also known as the anomalous expansion of water is the reason why water bottles crack on freezing of the water inside.

Another effect of this is the floating of ice cubes in water. It is because ice is of lesser density than water due to the reason mentioned above. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment.

All rights reserved. What else do they know from their experiences about ice and water? Some children may observe that the ice "grows" or expands in the ice cube tray. Provide the children with the materials and their Ice Investigator Journals. Have each child label their two cups with their names on the side.

Have each child fill their two cups with water to identical levels between half and three-quarters full. They should carefully mark the levels of the water in the cups. Have them carefully cover each cup with foil and secure it like a lid. Have the children weigh their cups of water on the kitchen scale and mark the weight on the cup.

What do they think will happen? Why did they cover the cups with the foil? This prevents another state change — the change of liquid water into water vapor through the process of evaporation! Have the children record their ideas and information from their experiments in their Ice Investigator Journals.