Fossils: Relative and Absolute Dating

If the half-life of a radioactive group of atoms is 100 years, then how old is the rock if there 25% parent isotope left?

• 50 years

• 100 years

• 200 years

• 300 years

Tags

NGSS.HS-PS1-8

Put the layers in order from oldest to youngest.

• a, b, c, d, e

• b, c, d, a, e

• b, c, d, e, a 

• e, d, c, b, a

Tags

NGSS.MS-ESS1-4

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

• 37.5 years

• 100 years

• 600 years

• 900 years

Tags

NGSS.HS-PS1-8

Which rock layer in the diagram seems to be the oldest?

• F

• B

• E

• A

Tags

NGSS.MS-ESS1-4

Radiometric dating is possible because the rates of decay of radioactive isotopes _____.

• change over time

• change from place to place

• are constant

• vary widely

Tags

NGSS.HS-PS1-8

What percent of carbon-14 would be left after 11,460 years? (2 half lives)

• 100%

• 75%

• 50%

• 25%

If one-fourth of the carbon-14 is remaining then how many half-lives have passed?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-8

After 22,800 years, approximately what percentage of the original carbon-14 remains?

• 15%

• 12.5%

• 6.25%

• 3.125%

What are the relative ages of the features in order from oldest to youngest?

• Limestone, Basalt, Fault, Siltstone

• Siltstone, Fault, Basalt, Limestone

• Limestone, Fault, Basalt, Siltstone

• Limestone, Siltstone, Fault, Basalt

Tags

NGSS.MS-ESS1-4

Which of the following methods is used to determine the absolute age of a fossil?

• Relative dating

• Radiometric dating

• Stratigraphy

• Biostratigraphy