Half-life

_________________ is a method of determining the absolute ages of rocks.

• Radioactive dating

• Radioactive decay

• Relative age

• Counting the rings of a rock

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NGSS.HS-PS1-8

________________ is the time it takes for half of the radioactive atoms in an element to decay.

• Half-life

• Radiation

• Relative age

• Full-life

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NGSS.HS-PS1-8

During _________________, the atoms of one element break down to form atoms of another element.

• radioactive decay

• relative dating

• absolute age

• tooth decay

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NGSS.HS-PS1-8

You find a rock sample with radioactive atoms present.  If 12.5% 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

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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

Using ESRT (A) [Radioactive Decay Data], what is the half-life in standard notation of carbon-14?

• 5,700 years
• 57,000 years
• 570,000 years
• 5,700,000 years

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NGSS.HS-PS1-8

Using ESRT (A) [Radioactive Decay Data], what is the half-life in standard notation of Uranium-238?

• 4,500 years
• 450,000 years
• 4,500,000 years
• 4,500,000,000 years

Tags

NGSS.HS-PS1-8

Which radioactive isotope takes the greatest amount of time to undergo radioactive decay? 

• Carbon-14
• Potassium-40
• Uranium-238
• Rubidium-87

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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

Potassium-40 is useful for radioactive dating of Earth's rocks because the half-life of potassium-40 

• decreased as the amounts of ⁴⁰Ar and ⁴⁰Ca in the rock increased
  
• remained constant during the radioactive decay process
  
• increased as pressure from the overlying sedimentary rock increased
  
• was shortened by the high temperature of the magma that formed the rock 

Tags

NGSS.HS-PS1-8