Fizzy drinks – A question from Nicholas (11)

Nicholas asked a question about his fizzy drink – “When you open a can of fizzy pop, what keeps the bubbles in the liquid? Why does it go flat slowly and not all at once, as soon as you open the can?” I asked my friends about this.

water bubbles copy
The experiment involved slowly warming a saucepan of water. Long before it boiled lots of bubbles appeared. These were not steam bubbles but bubbles of air and they were slowly coming out of the water. There were no bubbles before I started heating the water. So where were they? Where were they hidden in the water? You might not believe it, but in water and other liquids, there is quite a lot of space for the air to hide itself. Your fizzy drink had quite a lot of space to hide the gas particles that they put in fizzy drinks (carbon dioxide).

Let me tell you about how I devised an activity to explain how this space came about in solids, liquids and gases.

Imagine you are with a group of people and you are asked to imagine that each of you is a particle of a solid – let’s say ice. Because you are a solid you will not be moving (you might be vibrating slightly). You will probably be part of a lattice of non moving particles. They were non-moving because it was ‘cold’ and  they had been asked to put their hand on to a shoulder of the person next to them.  I then told them that things were getting hotter (getting hotter, means giving them more energy) and that the firm bonds were going to break BUT they still had to remain in some loose contact with each other. As it got hotter they were to move more quickly around the room but they still had to be touching somebody else all the time. It was just a touch, maybe one hand touching another, no holding and they could  move from person to person but always be in a situation where they were touching somebody. They were no longer a solid they were a liquid. I then asked them to STOP and look at the space they had created …..space for air bubbles, and fizzy drink bubbles, space for other solids to hide in. (revised 24/7/2016)

What do you think happens when things get even hotter and everyone  is moving a lot faster? What will the particles become?

Sorry for the long explanation. I hoped it helps in your own understanding.

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