Absolute Dating vs Relative Dating

Front

What is Absolute Dating?

Back

A method used to determine the exact age of a rock or fossil in years, often using radioactive decay.

Front

What is Relative Dating?

Back

A method used to determine the age of rocks or fossils in relation to one another, without providing a specific age.

Tags

NGSS.MS-ESS1-4

Front

What is a Half-Life?

Back

The time required for half of the radioactive atoms in a sample to decay.

Tags

NGSS.HS-PS1-8

Front

If the half-life of a radioactive group of atoms is 100 years, how old is the rock if there have been two half-lives?

Back

200 years.

Tags

NGSS.HS-PS1-8

Front

What does the Principle of Superposition state?

Back

In an undisturbed sequence of rock layers, the oldest layer is at the bottom.

Front

How does Absolute Age differ from Relative Age?

Back

Only absolute dating finds the age in years.

Front

If the half-life of a radioactive group of atoms is 300 years, how old is the rock if there have been three half-lives?

Back

900 years.

Tags

NGSS.HS-PS1-8

Front

How many half-lives have passed if there is 12.5% parent isotope left?

Back

3 half-lives.

Front

What is the significance of the Principle of Cross-Cutting Relationships?

Back

It states that a rock or fault that cuts through another rock must be younger than the rock it cuts.

Tags

NGSS.HS-ESS1-5

Front

What are Inclusions in geology?

Back

Fragments of one rock type that are contained within another rock type, indicating that the rock containing the inclusions is younger.