CO2
The carbonation in fizzy drinks cause them to fizz.
The fizz in the drinks are from carbon dioxide.
its all the fizz
Carbon Dioxide
Fizzy drinks are not fizzy in space as there is no oxygen to fizz the bubbles. The fizz in fizzy drinks is carbon dioxide coming out. In a vacuum the liquid would "boil" because of the water vapour coming out, and would probably freeze because of all the heat removed with it. Oxygen plays no role in this at all.
Fizzy drinks have carbonic acid which produces the carbon dioxide that makes the drinks fizz; they also usually have phosphoric acid, for flavor.
Carbon dioxide.
Fizz in fizzy drinks is dissolved carbon dioxide (CO2) coming out of solution. That's all that is in fizz.
carbon dioxide
The gas dissolves when under pressure in a liquid. When the pressure is released the gas expands rapidly causing the fizz.
Fizzy soft drinks contain many chemicals. One of these is citric acid - a weak acid that is naturally found in citrus fruits such as oranges, lemons and limes. It is added to soft drinks to give a slightly sour taste, to stabilise the 'fizz' and also to serve as a preservative.
The carbonic acid decomposes, causing water and carbon dioxide - you see the carbon dioxide as bubbles.