What is a crystal?
A crystal refers to a smaller group of molecules of any substance that forms a fixed geometric shape when transitioning from a liquid to a solid state.
To better understand crystals, let’s consider an example using sugar. Take a glass of water and add sugar, stirring continuously until the sugar is completely dissolved.
After some time, you will notice that the sugar no longer settles at the bottom of the glass. This indicates that the water has absorbed the maximum amount of sugar it can hold, forming what is known as a saturated solution.
Now, place this glass of sugar solution (saturated sugar solution) on a heat source and heat it at a constant temperature. Let’s say the initial temperature was 20°C, and you heat it to 60°C. While heating, continue adding sugar and stirring the solution. Eventually, you will observe that the sugar stops dissolving even in the warm solution. At this point, stop adding sugar.
Remove the heat source and allow the solution to cool slowly to room temperature under normal atmospheric conditions without disturbing it. As the solution cools, tiny grains of sugar will begin to precipitate, forming crystals. When observed under a microscope, these grains will exhibit a similar geometric shape, such as circular, rectangular, hexagonal, or any other shape that is consistent among all the grains.
The surface of each grain will be smooth, and the size and shape of one grain will closely resemble the others. These unique properties of the grains are what make them known as crystals.
By following this simple example, you can gain a basic understanding of how crystals form. Crystals are present in various substances and play a significant role in fields such as chemistry, geology, and materials science.
I hope this explanation helps you grasp the concept of crystals more easily! 😊