Have you ever wondered why the container of crystal clear water that you placed inside the freezer came out looking cloudy and not clear? Here are some reasons why it turned out that way.
Impurities in the Water
Water does not solely consist of H2O. While you may see that the water is clear and clean, there are actually microscopic and harmless sediments and minerals in it. In liquid water, these impurities cannot be seen by the naked eye. But when water freezes, these impurities are trapped, which make the ice look cloudy.
Tiny Air Bubbles
Aside from water impurities, trapped air is also responsible for the cloudy look. Even if the water is free of minerals and other impurities, there can be air fused in with the water. As the water freezes, entrapped air moves out of the freezing ice toward the part where it is unfrozen, usually at the center. The trapped air then becomes frozen water with air bubbles, making it look cloudy.
Ice Crystal Formation
A glassy pattern is formed when molecules position themselves as the water freezes into ice. This pattern, though, is different for every ice since it depends on how the ice is formed. If the water is pure and has little oxygen in it, it freezes slowly and creates a large crystal pattern and looks nearly invisible. But if freezing is rapid, there are many tiny crystals within the bigger overall pattern. These small crystals refract light and appear to look cloudy.
