Geologic Time and Radioactive Dating

The age of a rock given as the number of years since the rock formed is called _______________.

• relative age

• half-life

• absolute age

• radioactive decay

Tags

NGSS.HS-PS1-8

Where would you find the oldest fossils?

• at the top

• at the bottom

• in the middle

Tags

NGSS.HS-ESS2-1

NGSS.HS-LS4-5

Why is Carbon-14 dating used for plant and animal fossils?

• It is found in all living organisms

• It has a very long half-life

• It shows layers better

• It is older than the sample

The time it takes half of the atoms of a radioactive element to decay is the element's ________________.

• relative age

• half-life

• absolute age

• radioactive decay

Tags

NGSS.HS-PS1-8

A bone contains 12.5 percent of the carbon-14 it began with. How old is the bone?

• 3.9 billion years old

• 1,910 years old

• 17,190 years old

• 458.4 years old

Tags

NGSS.HS-PS1-8

Determining whether an object or event is older or younger than other objects or events is called ______________.

• Relative dating

• Super-position

• Geologic column

• Half life

Why is Potassium-40 dating used for ancient rocks?

• It is found in all living organisms

• It has a very long half-life

• It shows layers better

• It is older than the sample

Tags

NGSS.HS-ESS1-6

A rock contains 25 percent of the Potassium-40 it began with. How old is the rock?

• 2.6 billion years old

• 52 million years old

• 11,460 years old

• 32.5 years old

What is radioactive dating used for?

• to determine where a rock or fossil came from

• to determine the relative age of a rock or fossil

• to determine absolute age of a rock or fossil

Tags

NGSS.HS-PS1-8

After every half-life, a portion of radioactive element is:

• replaced by 50% of stable element

• decreased by 25% of stable element

• increased by 1/2 of stable element

Tags

NGSS.HS-PS1-8