Simple science - Bouncy eggs

As part of our learning in literacy, Huia Whanau have been focusing on the anatomy of the human body. We've previously been learning about the skeletal system and the structure of our bones. We did a simple science experiment to help our understanding around the different layers of human bone.

We started by researching the difference between calcium and calcium carbonate. We learnt that calcium is a product that makes the outer layer of our bones strong, and we commonly get it from food sources such dairy products and seeds. We then learnt calcium carbonate is a compound product, meaning it is made up of two ingredients, much like compound word or a compound sentence. Calcium carbonate is 60% calcium and 40% carbonate, which is a chalk-like substance we get from rocks such as limestone.

Calcium carbonate is a product that people take if their diet is lacking in calcium. This helps them to make sure they are getting enough calcium. However, overuse over a long period of time, can cause damage to the kidney - this is because the added carbonate isn't healthy for human consumption.

We learnt that egg shells are similar to human bones, and made from calcium carbonate. Like human bones, the outer layer is strong and designed to protect. Also like the human bone, the inner layer acts as a sponge. We submerged our raw eggs in a glass jar filled with white vinegar. We then left them sitting for 4 days. Over the 4 days, we saw some changes in our eggs as the outer layer was no longer protecting the egg, and the second layer was beginning to soak up the vinegar. Our eggs lost their brownish colour, grew in size, and began to sink to the bottom of the jar.

After the final day, we removed our eggs and took them to the top court to see if they would bounce. Some eggs broke as soon as they were pulled from the jar, while others were successful in bouncing. Those that were successful, however, only bounced a few times before breaking as well.