Radiometric

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

Radiometric dating is possible because the rates of decay of radioactive isotopes _____.

• change over time

• change from place to place

• are constant

• vary widely

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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

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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

Radioactive decay happens when a(n)​ (a)   atom will change it's nucleus to become a​(n) ​ (b)   atom.

• unstable

• stable

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NGSS.HS-PS1-8

Radioactive decay happens when a(n)​ (a)   atom will change it's nucleus to become a​(n)​ (b)   atom.

• unstable

• stable

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 characteristic of the radioactive isotope uranium-238 that makes this isotope useful for accurately dating the age of a rock is the isotope’s 

• organic origin

• constant half life

• common 
  occurrence in sediment

• resistance to weathering

Tags

NGSS.HS-PS1-8