This is one I’ve wanted to do for a long time because I think it’s fascinating – to be able to peer into an unbroken egg is a bit like being able to look inside a body and see things how they normally are, not as they are once we’ve broken them. As you can see it’s another video special, we went quite sciencey this time with labels and testing different things, and it’s nice that the little girl (3) can participate more. Big girl (5) shows a lot of promise as a demonstrator, she decided what to say for herself and got it all out without me interrupting.
We tested both raw and boiled eggs, in carbonated water and vinegar. Anything carbonated is slightly acidic which is why we tested that as well. The full video is 6 minutes, if you want to do this with kids I seriously recommend you watch the whole thing with them. But for the time poor I’ve included the highlights.
And if you really don’t want to watch, you basically put eggs into a container and pour vinegar over them as shown below. It will work with both raw and boiled eggs, raw eggs are just more delicate. The bubbles are carbon dioxide from exactly the same acid/carbonate reaction you get in volcanoes, bath bombs and sherbert but rather than using sodium bicarbonate it uses calcium carbonate from the egg shell. This is what makes it hard, so when you take it out the shell gets very soft. You can dissolve it entirely and be left with just the membrane.
After about 30 hours we checked them, the sparkly water hadn’t done anything but the vinegar had completely dissolved the shells.
Only the membrane was left, the raw eggs were transparent.
They had also absorbed the vinegar making them significantly bigger than the boiled eggs.
This is more than just a fun thing to do with kids, it’s very important environmentally. As the world warms and the carbon dioxide increases, more of it is dissolved in sea water. This makes the water acidic because dissolved carbon dioxide makes carbonic acid, exactly the same as cool drinks. The reason Coke will dissolve a tooth left in it is not anything inherently evil about Coke, but the same reaction we are seeing here. And unfortunately for shellfish, their shells are made of calcium carbonate just like the chicken eggs, and they will have great difficulty growing them if the ocean becomes more acidic, among all the other problems of environmental change.
That’s a lot of animals and a lot of ecosystems that could collapse. Unfortunately the first thing we need to do about it is to stop pumping carbon dioxide into the atmosphere and possibly capture some that’s already there. Yet another reason to be more green.
Have some fun and let me know how it goes!
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