Some liquids form bubbles more easily than others. For example, by shakinga bottle of drinking water, some bubbles will form but will not last long. If you add some detergent to wash vaijllas (dishwasher) and is then stirred, will create a lot of bubbles and last longer.Bubbles can be formed with any two fluids (liquids or gases) that do not dissolve each other, not only with liquids and air. For example, oil and water (like the one found in "lava lamps").
Whentwo fluids are stirred together (eg water and air) are mixed. Since it does not dissolve easily with each other *, the heavier, the water in this case, try to settle on the bottom because of gravity,while the lighter, the air in this example, attempt to reach the top. For the liquid to settle, you must return and release the trapped air bubbles produced by the mixture. A force that the fluid hasto return in this situation is called "surface tension". Liquids with great strength or surface tension can easily return and settle. In this case, you will not see bubbles or they will not last long.The detergent reduces the surface tension of water, making it "weak" to reintegrate itself. Thus, the trapped air remains trapped for longer.
You can find more information on the Internet if yousearch "surface tension" and "bubbles."
* For the part where I write "do not dissolve easily with each other", in reality, most of the fluids dissolve, even a little. For example, a small amount ofair does not dissolve in water. Thus, "breathe" the fish, removing the air dissolved in the water. The amount of air that can be dissolved in water is called "solubility." When you reach that amount,known as "saturated" and no more air can be dissolved in water. As water heats up, less air can dissolve in it. This is the reason why you should never put a live fish in a tank with water that has...