Absolute Dating

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.

Tags

NGSS.HS-PS1-8

Which radioactive isotope should be utilized to date a rock from the Archean Eon?

• Carbon-14

• Nitrogen-14

• Calcium-40

• Uranium-238

Answer explanation

Uranium-238 has a long half-life so it will be utilized to date very old things.

Tags

NGSS.HS-PS1-8

Every half-life the % of a radioactive isotope is cut in ​ ​ (a)  

• half
• quarters
• sixths
• pieces

Answer explanation

100% / 2 = 50% parent for 1 hl

50% / 2 = 25% parent for 2 hl

25%/ 2 = 12.5% parent for 3 hl

Tags

NGSS.HS-PS1-8

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

The time it takes for 50% of the nuclei in a radioactive sample to decay to its stable isotope is called _____.

• the daughter product
• geologic time
• the half-life
• the half-time

Tags

NGSS.HS-PS1-8

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

• daughter element

• half-life

• parent element

• carbon-14

Tags

NGSS.HS-PS1-8

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

• daughter element
• half-life
• parent element
• carbon-14

Tags

NGSS.HS-PS1-8

How does absolute age differ from relative age?

• only absolute dating indicates which rock is older than another
• only absolute dating finds the age in years
• only relative dating finds the age in years

Tags

NGSS.MS-ESS1-4

A rock with 50% ¹⁴C has an age of

Answer explanation

50% of a radioactive isotope (like carbon-14) is 1 half-life (5700 years).

Tags

NGSS.HS-PS1-8

A rock with 25% ¹⁴C has an age of

Answer explanation

25% of a radioactive isotope (like carbon-14) is 2 half-lives (5700 years x 2 = 11,400 years).