Whether you celebrate Easter or not, you’ll love these ideas for eggy-science fun with your child over the long weekend – using simple ingredients from the cupboard!
Here’s what you need:
- One raw egg
- One cup vinegar
- One clear jar or glass
- Paper and pen/pencil to write observations
Here’s what to do:
- Get your child to pour the cup of vinegar into the jar/glass, and then gently place the egg into the vinegar. The egg should be completely covered.
- Ask your child to record what they see (observations) using the paper and pen/pencil. (Hint: there will be bubbles rising from the egg.)
- Ask your child to put the jar somewhere safe and leave the egg in the vinegar for one day.
- Get your child to remove the egg and feel it, and record their observations. (Hint: the egg shell will be soft).
Why does this happen?
If you want to talk about the chemistry behind this experiment with your child, here’s what’s happening – egg shells contain something called ‘calcium carbonate’. This is what makes them hard. Vinegar is an acid known as ‘acetic acid’. When calcium carbonate (the egg shell) and acetic acid (the vinegar) combine, a chemical reaction takes place and carbon dioxide is released – this is what the bubbles are made of. The chemical reaction keeps happening until all of the carbon in the egg is used up. When you take the egg out of the vinegar it’s soft because all of the carbon floated out of the egg shell in those little bubbles.
But wait there’s more…
Here are some easy variations on this experiment you can try with your child.
- Ask your child to leave the soft-shelled egg sitting out on a clean, dry surface for another day.
- Get your child to feel the egg again and record their observations. (Hint: It will be hard! The egg shell will have absorbed carbon back from the carbon dioxide that’s in the air.)
- Ask your child to place the soft-shelled egg in water and keep checking on it and recording their observations. (Hint: the egg will absorb the water and expand until the shell finally bursts!)
Bounce it! (Just be prepared for some mess!)
- Ask your child to put the egg back in the vinegar and leave it for another couple of days.
- Help your child to carefully rinse the egg, rubbing the shell gently – it should come off. (Leave it for another day in the vinegar if some shell remains and then rinse carefully again until the shell has completely gone.)
- Once the shell is removed get your child to try to bounce the egg – recording their observations as they go. First ask them to drop the egg carefully from quite a low height – the egg should bounce up from the surface. Then get them to try bouncing the egg on different surfaces, and/or to keep increasing the height from which they drop the egg until it breaks!
Colour it! (A less-mess option!)
- If you don’t want to worry about the bouncing-egg-mess, change the egg’s colour instead!
- Ask your child to put the shell-less egg in a jar of water.
- Get your child to add a few drops of food colouring to the water and wait for a few hours.
- Ask your child to remove the egg from the coloured water and record their observations. (Hint – the egg should turn the same colour as the water!)