Nuclear Day 3 - Half-life

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

According to the graph, if 1.0 gram of radioactive material existed at time t = 0, how much still exists after 3 half lives?

• 0,5000 g

• 0,2500 g

• 0,1250 g

• 0.0625 g

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?

• zero

• 1

• 2

• 3

Tags

NGSS.HS-PS1-8

Suppose you found a material in which 12.5% (i.e., 1/8) of the original radioactive atoms were still present. If the half-life of an atom is 60 years, how old is the material?

• 30 years old

• 60 years old

• 120 years old

• 180 years old

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 decay of a radioactive material over time. 
How long does it take for this radioactive material to decay through 2 half-lives? 

• 1 x 10³ years
• 5 x 10³ years
• 10 x 10³ years
• 40 x 10³ years

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

If one quarter of a sample is left after 200 years what is the half-life of the sample?

• 200 years
• 400 years
• 100 years
• impossible to tell

Tags

NGSS.HS-PS1-8

Uranium-238  decays into  Thorium-234  by emitting .........

• an alpha particle
• a beta particle
• gamma rays
• visible light

Tags

NGSS.HS-PS1-8