Many young postgirls are wondering: does water expand or contract when it freezes ? The answer is: with the advent of winter, water begins its expansion process. Why is this happening? This property distinguishes water from the list of all other liquids and gases, which, on the contrary, are compressed during cooling. What is the reason for this unusual fluid behavior?
Class 3 physics: does water expand or shrink when it freezes?
Most substances and materials increase in volume when heated and decrease when cooled. Gases show this effect more noticeably, but various liquids and solid metals exhibit the same properties.
One of the most striking examples of the expansion and contraction of gas is air in a balloon. When we take the balloon outside in negative weather, the balloon immediately decreases in size. If we bring a ball into a heated room, then it immediately increases. But if we bring a balloon into the bathhouse, it will burst.
Water molecules require more space
The reason that these processes of expansion and contraction of various substances occur is the molecules. Those that receive more energy (this happens in a warm room) move much faster than molecules in a cold room. Particles that have a lot of energy collide much more actively and more often, they need more space for movement. To contain the pressure exerted by the molecules, the material begins to increase in size. Moreover, this is happening quite rapidly. So, does water expand or contract when it freezes? Why is this happening?
Water does not obey these rules. If we begin to cool water to four degrees Celsius, then it reduces its volume. But if the temperature continues to fall, then the water suddenly begins to expand! There is such a property as an anomaly in the density of water. This property occurs at a temperature of four degrees Celsius.
Now that we have found out whether the water expands or contracts when it freezes, let's find out how this anomaly generally occurs. The reason lies in the particles of which it consists. A water molecule is made up of two hydrogen atoms and one oxygen atom. Everyone knows the formula of water since the elementary grades. Atoms in this molecule attract electrons in different ways. Hydrogen creates a positive center of gravity, while oxygen, on the contrary, creates a negative center of gravity. When water molecules collide with each other, the hydrogen atoms of one molecule transfer to the oxygen atom of a completely different molecule. This phenomenon is called hydrogen bonding.
Water needs more space when it cools
At the moment when the process of formation of hydrogen bonds begins, places begin to appear in the water where the molecules are in the same order as in the ice crystal. These blanks are called clusters. They are not durable, as in a solid crystal of water. With increasing temperature, they are destroyed and change their location.
During the process of cooling water , the number of clusters in the liquid begins to increase rapidly. They require more space for distribution, as a result of which water also increases in size after reaching its anomalous density.
When the thermometer column falls below zero, the clusters begin to turn into tiny ice crystals. They begin to rise up. As a result of all this, water turns into ice. This is a very unusual ability of water. This phenomenon is necessary for a very large number of processes in nature. We all know, and if we donโt, we remember that the density of ice is slightly less than the density of cool or cold water. Due to this, ice floats on the surface of the water. All water bodies begin to freeze from top to bottom, which allows you to live quietly and not freeze the water inhabitants at the bottom. So, now we know in detail about whether the water expands or contracts when it freezes.
Interesting phenomenon
Hot water freezes faster than cold. If we take two identical glasses and pour hot water in one and the same cold water in the other, we will notice that hot water will freeze faster than cold water. This is not logical, agree? Hot water needs to cool to start freezing, but cold is not necessary. How to explain this fact? Scientists to this day cannot explain this riddle. This phenomenon is called the โMpemba Effectโ. It was discovered in 1963 by a scientist from Tanzania under an unusual set of circumstances. The student wanted to make himself ice cream and noticed that hot water freezes faster. He shared this with his physics teacher, who at first did not believe him.