Why does ice occupy more volume

It has to freeze. At what temperature does water turn into ice? Can they think of any examples in their lives when they make ice from water? Some children may share that they have made ice cubes or popsicles in their freezers. 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.

At sufficiently cold temperatures, usually around 0 degrees Celsius 32 degrees Fahrenheit , water undergoes a phase transition to ice called freezing. This is because as the temperature becomes colder, the water molecules lose energy and move less.

The hydrogen bonds that form when water freezes into ice allow the molecules to be spaced farther apart, thus making them take more space, decreasing the overall density and making it float in the water. The reason that density determines if something will float or sink is because, as stated by Newton's third law:. Why does ice float on water? Chemistry Measurement Density.

Kuba Dolecki. Jan 21, Ice floats on water because it is less dense than water. Ahmed Elnaiem. 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. Water is one of the few exceptions to this behavior. When liquid water is cooled, it contracts like one would expect until a temperature of approximately 4 degrees Celsius is reached.

This unusual behavior has its origin in the structure of the water molecule. There is a strong tendency to form a network of hydrogen bonds, where each hydrogen atom is in a line between two oxygen atoms.