Radiometric Dating and Radioactive Decay

The length of time required for half of the radioactive atoms in a sample to decay is its...

• era

• age

• half-life

• eon

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

If the half-life of a radioactive group of atoms is 100 years, then how old is the rock if there have been two half-lives?

• 25 years

• 200 years

• 400 years

• 800 years

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 many grams of Carbon-14 will remain after 17,100 years- C-14 has a half life 5,730 so 17,100 is about 3 half lives?

• 32 g

• 16 g

• 8 g

• 4 g

Tags

NGSS.HS-PS1-8

What percentage of Rubidium-87 will remain after 4 half-lives?

• 25%

• 12.5%

• 6.25%

• 3.125%

Tags

NGSS.HS-PS1-8

You find a rock sample with radioactive atoms present.  If 25% of the original radioactive atoms were present, how many half-lives has the rock been around for? (Hint, at Half-Life = 0, you start with 100%)

• zero

• 1

• 2

• 3

Tags

NGSS.HS-PS1-8

The table shows the radioactive decay of carbon-14. Part of the table has been left blank.
After 22,800 years, approximately what percentage of the original carbon-14 remains?

• 15%

• 12.5%

• 6.25%

• 3.125%

Tags

NGSS.HS-PS1-8

The graph shows the generalized rate of decay of radioactive isotopes over 5 half-lives.
If the original mass of a radioactive isotope was 24 grams, how many grams would remain after 3 half-lives?

• 12

• 24

• 3

• 6

Tags

NGSS.HS-PS1-8

The graph shows the radioactive decay of a 50-gram sample of a radioactive isotope. 
According to the graph, what is the half-life of this isotope? 

• 100 years

• 150 years

• 200 years

• 300 years

Tags

NGSS.HS-PS1-8