• Question: why do bubbles rise to the top in fizzy drinks?

    Asked by naillic to Stephen, Colm, Eoin, Joseph, Lauren on 19 Nov 2013. This question was also asked by danniella1588.
    • Photo: Stephen Scully

      Stephen Scully answered on 19 Nov 2013:

      Air is lighter than water and so the bubbles (made from gas, like the air) floats to the top.

    • Photo: Eoin O Colgain

      Eoin O Colgain answered on 20 Nov 2013:

      Carbon dioxide is added to fizzy drinks. When the can is sealed it is under pressure and dissolves in the liquid. Once you open it, the pressure decreases and the carbon dioxide is released from the liquid, creating bubbles, which rise to the surface.

    • Photo: Lauren Mc Keown

      Lauren Mc Keown answered on 21 Nov 2013:

      The CO2 bubbles rise to the top because when you open a bottle, pressure is released. When the bottle is closed, the drink is carbonated and pressure has been used to keep the carbon dioxide in the liquid, so they stay there. This is why when you leave a bottle open for some time, the drink will go flat. Don’t ever do this to my Diet Coke…

    • Photo: Joseph Roche

      Joseph Roche answered on 21 Nov 2013:

      That’s just the bubbles of carbon gas escaping and it’s normal. But if the bubbles go to the bottom, instead of the top, that’s when you panic 😉