The Case of the Counterfeit Dinosaur Bones:
A Baking-Soda Rock Extension Activity

This activity takes a little bit of preparation to make a fun mystery activity for kids of all ages to solve. I recommend adults make the baking soda rocks and explain the reaction with kids ahead of time so they might be more successful with this mystery. You may also want to check out The Field Museum’s site on bones versus casts (https://www.fieldmuseum.org/blog/which-dinosaur-bones-are-real).

Adult set up:
Materials:
1/4 cup bleached flour (if it isn’t super bright white I recommend adding a drop or two of food coloring to each paste to make it harder to tell them apart)
2 tablespoons water
1/4 cup baking soda
2 tablespoons water
Eyedropper, spoon, straw
Vinegar

Procedure
1. Prepare a mixture of 1/4 cup white flour and 2 tablespoons water and mix into a thick paste, adding extra water if needed
2. Freeze mixture into a dinosaur bone candy or ice cube tray for about 2 hours until solid
3. Remove flour bones and place on a tray in freezer
4. Prepare a mixture of 1/4 cup baking soda and 2 tablespoons water and mix into a thick paste, adding extra water if needed
5. Freeze mixture into a dinosaur bone candy or ice cube tray for about 2 hours until solid
6. Remove baking soda bones and place on the tray (Keep them separate for now)
7. For the first step, give your child the flour bones and let them test them with acid (they shouldn’t react)
8. For the second step, mix up the baking soda and flour bones and let them separate the baking soda and flour bones based on their testing

Carbonate Bones (Baking Soda paste) should react like this with vinegar
Flour Cast Bones (Flour paste) should not react with vinegar

For the Student
Assignment:
(PDF can be found here or at https://www.ccssc.org/wp-content/uploads/2020/07/the-case-of-the-counterfeit-dinosaur-bones.pdf)

The Coca-Cola Space Science Center obtained their first dinosaur bones and they were so excited! Unfortunately some sneaky thieves came to the museum in the middle of the night and now museum workers are not sure if the bones are the real ones or just counterfeit casts of the bones. We need you to figure out if the carbonate bones are on display or if they were stolen!

We know that carbonate rocks react with acid (like vinegar!) Use your vinegar to test one of the bones you have to determine whether these are the carbonate bones or if they are fake counterfeit copies!

Were the bones stolen? How do you know? Report your findings to the museum security (the grown-up helping you).

The next day, museum workers arrived to an interesting site: a giant pile of dinosaur bones, it looked like there were enough for two dinosaurs! It turns out the casts and the bones have made it back to the museum but now there is a new problem: we need to make complete sets of the bones and casts without doing too much damage to the bones. Use your knowledge of carbonate rocks to help test and sort each of the “bones” and make complete dinosaur skeletons.

Were you successful? What were some problems you encountered?

Did you enjoy this activity? Please let us know and send an e-mail to us at info@ccssc.org