Section 3- Radioactive Dating Flashcards
What is a half-life?
Where half of a rock’s radioactive atoms have been replaced with a different element.
What are the three main ways geologists use radioactive dating to determine the absolute ages of rocks?
They use Potassium-Argon dating, Carbon-14 dating, and radioactive dating of rock layers.
What words do you use for relative age and absolute age?
You use words like ‘younger than’, ‘older than’, and ‘same age’ to describe relative age. You use numbers for absolute age.
What do scientists determine first when using radioactive decay to determine the age of rocks?
They first determine the amount of radioactive element in the rock. Then they measure the amount of the stable element in the rock.
What happens during radioactive decay?
Radioactive particles in the rock release atoms that changes the element into a different element.
How does the composition of a rock containing a radioactive element change over time?
The amount of radioactive element will decrease as the new element increases.
Can geologists determine sedimentary rocks’ absolute age using radioactive dating?
No because the particles that make up sedimentary rocks come from many different rocks. Those rocks are all different ages.
Can geologists determine extrusions and intrusions’ absolute age using radioactive dating?
Yes because radioactive element is naturally in igneous rocks. They are also not made up from other rocks like sedimentary rocks are.
What is an element?
When all the atoms of a particular type of matter are all the same.
