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.

Tags

NGSS.HS-PS1-8

Front

What is Relative Dating?

Back

A technique used to determine the age of rocks or fossils in relation to other rocks or fossils, without providing a specific age.

Front

What is a half-life?

Back

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

Tags

NGSS.HS-PS1-8

Front

If you start with 1000 parent atoms, how many will remain after 1 half-life?

Back

500 parent atoms.

Tags

NGSS.HS-PS1-8

Front

If the half-life of a radioactive isotope is 100 years, how old is the rock after two half-lives?

Back

200 years.

Tags

NGSS.HS-PS1-8

Front

If the half-life of a radioactive isotope is 300 years, how old is the rock after three half-lives?

Back

900 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.

Tags

NGSS.MS-ESS1-4

Front

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

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It states that a geological feature that cuts through another is younger than the feature it cuts.

Front

What is the Principle of Inclusions?

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It states that any rock fragments included in another rock must be older than the rock containing them.

Front

How do scientists use radioactive isotopes in dating?

Back

They measure the ratio of parent isotopes to daughter isotopes to determine the age of a sample.

Tags

NGSS.HS-PS1-8