The Earth is 4.565 billion years old, give or take a few million years. How do scientists know that? 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. Credit: The American Chemical Society
The Earth is 4.565 billion years old, give or take a few million years. How do scientists know that? 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:
