Exit Check 8.2 - Radiometric Dating

8.2.3

How is radioactive dating used to determine the absolute age of rocks?

• The percent of radioactive parent isotopes remaining in the rock is compared to the amount of stable daughter isotopes that are present

• it compares the radioactive isotope in a younger layer of rock to an older layer

• isotopes of different compounds are compared

• daughter isotopes are compared to sister isotopes

Answer explanation

This question links to success criteria 8.2.3: I can use appropriate radioactive isotopes to determine the absolute ages of rocks and organic objects. 

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

8.2.1

The element that is the product of radioactive decay is known as the...

• daughter element

• half-life

• parent element

• carbon-14

Answer explanation

This question links to success criteria 8.2.1: I can differentiate between a parent and daughter isotope in a radioactive decay process.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

Tags

NGSS.HS-PS1-8

8.2.1

The original element that undergoes radioactive decay is known as the...

• daughter element

• half-life

• parent element

• radioactive decay

Answer explanation

This question links to success criteria 8.2.1: I can differentiate between a parent and daughter isotope in a radioactive decay process.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

Tags

NGSS.HS-PS1-8

8.2.2

The diagram shows 32 atoms

8 of the Red are parent isotopes

24 of the Green are daughter isotopes

How many half-lives have occurred?

• 0

• 1

• 2

• 3

Answer explanation

This question links to success criteria 8.2.2: I can relate radioactive half-life to how long a substance has been decaying radioactively and how much substance remains.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

Tags

NGSS.HS-PS1-8

8.2.2

A sample of wood that originally contained 100 grams of carbon-14 now contains only 12.5 grams of carbon-14. If the half life of Carbon-14 is 5700 years, approximately how many years ago was this sample part of a living tree?

• 2,850 years

• 5,700 years

• 11,400 years

• 17,100 years

Answer explanation

This question links to success criteria 8.2.2: I can relate radioactive half-life to how long a substance has been decaying radioactively and how much substance remains.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

Tags

NGSS.HS-PS1-8

8.2.2

What is Half-life?

• The amount of time it takes for some of the nuclei in a sample of the isotope to decay

• The amount of time it takes for half the electrons in a sample of the isotope to decay

• The amount of time it takes for half the nuclei in a sample of the isotope to decay

• the amount of time it takes to double the nuclei in a sample of the isotope to decay

Answer explanation

This question links to success criteria 8.2.2: I can relate radioactive half-life to how long a substance has been decaying radioactively and how much substance remains.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

Tags

NGSS.HS-PS1-8

8.2.2

How many half-lives have passed if there 6.25% parent isotope left?

• 1 half-life

• 2 half-lives

• 3 half-lives

• 4 half-lives

Answer explanation

This question links to success criteria 8.2.2: I can relate radioactive half-life to how long a substance has been decaying radioactively and how much substance remains.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

Tags

NGSS.HS-PS1-8

8.2.3

Match the following radioactive isotopes to the time-frames they can be used to accurately measure.

• Accurate up to 3-4 billion years

• Potassium-40

• Accurate up to 500,000 years

• Carbon-14

• Accurate up to 50,000 years

• Uranium-235

• Accurate beyond 4 billion years

• Uranium-234

Answer explanation

This question links to success criteria 8.2.3: I can use appropriate radioactive isotopes to determine the absolute ages of rocks and organic objects. 

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

8.2.3

Which radioactive isotope should be utilized to date a mummy?

• Carbon-14

• Nitrogen-14

• Potassium-40

• Uranium-238

Answer explanation

Carbon-14 has a short half-life so it will be used to date recent things.

This question links to success criteria 8.2.3: I can use appropriate radioactive isotopes to determine the absolute ages of rocks and organic objects. 

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark

8.2.3

Which of the following reasons explains why scientists cannot use Carbon-14 to date the bones in this dinosaur fossil?

• Carbon-14 has a short half-life so it is only useful to date recent things.

• Dinosaur bones do not contain carbon or carbon-14

• Dinosaurs were not radioactive because they never invented nuclear power plants

• Scientists have not yet calculated the half-life of carbon-14

Answer explanation

This question links to success criteria: I can use appropriate radioactive isotopes to determine the absolute ages of rocks and organic objects. 

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark