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How Do We Know How Old the Earth Is?
Season 4
Episode 31
Since there’s no “established in” plaque stuck in a cliff somewhere, geologists deduced the age of the Earth thanks to a handful of radioactive elements. With radiometric dating, scientists can put an age on really old rocks — and even good old Mother Earth. For the 30th anniversary of National Chemistry Week, this edition of Reactions describes how scientists date rocks.
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15:58
Fluffy, delicious bread results when starch gelatinization and flour chemistry combine!

12:35
Join George (and, occasionally, Andrew) as they chart corn’s epic chemical journey.

10:46
We explore and learn anywhere between the 20 and 74,963 kinds of ice.

10:34
For years it was used in homicidal poisonings. We learn what made it so dangerous.

12:40
We explore brining and whether or not it makes a different when cooking the turkey.

15:23
We dive into the science to figure out how to make gummies without the side effects.

18:01
There are a few obstacles to overcome before we get there.

13:15
Come along on George’s epic journey into the wilds of salt science!

9:41
Weeds are building a defense against today's herbicides.

17:15
We explore how far carbon structures are from revolutionizing the world.

14:45
We dig into the science of flavor pairings, especially when it comes to the famous combo.

10:39
Can a medicine cause a war? The treatment for Malaria may just have.