Water provides sustenance, without which most life forms would not survive. Thus, evolutionary scientists have theorized that life on Earth is primarily facilitated by the abundance of water on the planet. Therefore, when searching for indications of extraterrestrial life on other planets, one of the first things evaluated is whether the planet has water.
Humans, along with many other species, need to drink water regularly to survive and function properly. This makes water an essential component in our lives, but as a chemical compound or as a liquid, water has many properties that are unusual and different from ordinary liquids.
In a gaseous state, water is an extremely light gas; however, it is even denser than its solid structure in its liquid state. These unconventional characteristics of water have an immense impact on our lives, thus making it important for individuals to know more about it. This article will examine the properties of water and its anomalous expansion.
Listed below are the general characteristics associated with water:
Usually, it is seen that compounds expand when exposed to heat while simultaneously decreasing their density, and conversely, their density increases, and matter contracts when cooled. This is considered the ordinary behavior of substances when reacting to heat. However, the properties of water deviate from this normal, and this will be explained subsequently.
As long as the temperature of the water is not below 4 degrees Celsius, it behaves ordinarily in the manner explained above. However, as soon as it is cooled further, its unusual properties are highlighted.
As water is cooled, the density slowly increases until it reaches a maximum of 4 degrees Celsius. If it is cooled further to arrive at the ice form at 0 degrees Celsius, the density of water starts decreasing, and the matter expands. This unusual phenomenon known as the anomalous property of water occurs between temperatures of 4 degrees Celsius to 0 degrees Celsius.
The effect of this property means that since water is at its heaviest at 4 degrees Celsius in a water body, this temperature of water settles at the bottom. In contrast, the water which is at 0 degrees Celsius or at its coldest will be found on the surface of the water body. This implies that during the colder months, the surface of a water body is colder and will turn to ice first.
However, because both ice and water are not good conductors of heat, the cold weather does not freeze water beyond the top layer of the water body, thereby protecting all the life forms living in the sea, ocean, lake, etc. This anomalous property of water is so essential to organisms that live in the ocean as otherwise they would all freeze and turn into ice.
The chemical composition of water comprises two hydrogen atoms and one oxygen atom, and at ordinary temperature, these molecules stick together because of the attraction within the molecules. However, when water is in liquid form, these molecules constantly move around and are regularly rearranged.
As it gets colder, these molecules stick closer together, increasing their density until the maximum at 4 degrees Celsius. After that, the water molecules start favoring the attraction of the hydrogen-oxygen molecule over the oxygen-oxygen arrangement, and since this is not as strong, the water expands after 4 degrees Celsius.
Water is an essential compound for the survival of most life forms, and there is no denying that. However, what makes water unique are the properties elaborated above, and understanding them is a key step in making sense of the world we live in.