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Coral Chemistry

This is a fun activity where you can build your own coral structure out of eggshells and explore the impact that acid can have on undersea creatures. I had fun making my own coral-like structure. (See picture).

If you have an allergy to eggs you can use sidewalk chalk or seashells instead for this experiment

What you will need is:

2 eggshells (from eggs that have been used)

250 ml (1 cup) water

250 ml (1 cup) white vinegar

2 transparent cups or small containers

Hot glue gun and glue sticks Only an adult should use the hot glue gun

What you need to do is:

1. Build two small coral-like structures out of the used eggshells. Have the adult stick the pieces together using the hot glue gun.

2. Glue one structure to the bottom inside each cup.

3. Fill one cup with water and the other cup with vinegar.

4. Try to guess what will happen to each coral-like structure you have made after soaking in the liquids for 24 hours. You can even take pictures as your experiment progresses.

What is happening you may ask?

Coral is made of the same material as eggshells. It is layers of calcium carbonate. Did you see bubbles in the vinegar cup? That is a chemical reaction between the vinegar and the calcium carbonate. This is because vinegar is an acid. Over time the vinegar breaks down the shells. This is what is happening in our oceans because greenhouse gases make the water more acidic. The acid that is created will break down the coral and seashells in the ocean.

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