Absolute Dating vs Relative Dating

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What is Absolute Dating?

Back

A method used to determine the exact age of a rock, fossil, or artifact, often using radiometric techniques.

Front

What is Relative Dating?

Back

A method used to determine the age of rocks and fossils in relation to one another, without determining their exact age.

Front

What is an Index Fossil?

Back

A fossil that is used to define and identify a particular time period in the geological time scale, typically widespread and existed for a short duration.

Front

What does the Law of Superposition state?

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In undisturbed rock layers, the oldest layers are at the bottom and the youngest are at the top.

Tags

NGSS.MS-ESS1-4

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What is a Half-Life?

Back

The time required for half of the parent isotope in a sample to decay into a daughter isotope.

Tags

NGSS.HS-PS1-8

Front

If 75% of a parent isotope remains, how many half-lives have passed?

Back

1 half-life.

Tags

NGSS.HS-PS1-8

Front

If 50% of a parent isotope remains, how many half-lives have passed?

Back

1 half-life.

Tags

NGSS.HS-PS1-8

Front

If 25% of a parent isotope remains, how many half-lives have passed?

Back

2 half-lives.

Tags

NGSS.HS-PS1-8

Front

What is the significance of the Half-Life in Absolute Dating?

Back

It allows scientists to calculate the age of a sample based on the remaining amount of parent isotope.

Tags

NGSS.HS-PS1-8

Front

How can Index Fossils help in Relative Dating?

Back

They can indicate the relative age of rock layers by showing that they were formed during the same time period.

Tags

NGSS.MS-ESS1-4