Dissolving Gases Into Water

Many popular drinks are carbonated. This means they have carbon dioxide dissolved into them under pressure. When you open the bottle or can containing the drink, the pressure is released and the drinks starts to release bubbles - it becomes fizzy. This is why such drinks are called fizzy drinks.
Carbon dioxide is not poisonous. Our bodies breathe carbon dioxide in and out all the time. It is in the air we breathe.
many gases can be dissolved into water. Water contains dissolved oxygen. Fish pass water through their gills and absorb the dissolved oxygen into their bloodstream.In a fish tank, air must be pumped through the water, or water must be fed through a fountain to create bubbles so that oxygen can dissolve into the water for fish to breathe.