Earth's History and Geologic Time Flashcard

Front

What is the term for the amount of time it takes for half of the radioactive atoms in an isotope to decay?

Back

Half-life

Tags

NGSS.HS-PS1-8

Front

What methods can scientists use to determine the ages of fossils?

Back

All of the above (radiometric dating, stratigraphy, and biostratigraphy)

Front

How old do paleontologists believe the Earth is?

Back

4.6 billion years old

Tags

NGSS.MS-ESS1-4

Front

What is the difference between absolute age and relative age?

Back

Only absolute dating finds the age in years.

Front

What type of fossil is best used to determine the age of the rock layer in which it is found?

Back

Index fossil

Front

What is radiometric dating?

Back

A method used to date materials by comparing the abundance of a radioactive isotope to its decay products.

Tags

NGSS.HS-PS1-8

Front

What is the significance of index fossils in geology?

Back

Index fossils are used to identify and date the rock layers in which they are found.

Tags

NGSS.MS-ESS1-4

Front

What is the principle of superposition in geology?

Back

In an undeformed sequence of sedimentary rocks, the oldest layers are at the bottom and the youngest are at the top.

Tags

NGSS.MS-ESS1-4

Front

What is stratigraphy?

Back

The study of rock layers (strata) and layering (stratification).

Tags

NGSS.MS-ESS1-4

NGSS.MS-ESS2-3

Front

What is the geological time scale?

Back

A system of chronological dating that relates geological strata to time.

Tags

NGSS.MS-ESS1-4