3/27(W): Chemistry Checkpoint #30

Which radioisotope requires long-term storage as the method of disposal, to protect living things from radiation exposure over time?

• Nitrogen-16

• Neon-19

• Plutonium-239

• Radium-226

Which radioisotope in the image has the fastest rate of decay?

• Nitrogen-16

• Neon-19

• Plutonium-239

• Radium-226

• Phosphorus-32

Match the fraction of radioactivity remaining to the correct number of half-lives

• 1/32 radioactive

• 3 half lives

• 1/16 radioactive

• 5 half lives

• 1/2 radioactive

• 4 half lives

• 1/4 radioactive

• 1 half life

• 1/8 radioactive

• 2 half lives

A radioactive isotope has a half-life of 2.5 years. Match the correct fraction of the original mass that remains unchanged after the given amount of years

• 1/16 radioactive

• 10 years

• 1/32 radioactive

• 12.5 years

• 1/2 radioactive

• 5 years

• 1/8 radioactive

• 7.5 years

• 1/4 radioactive

• 2.5 years

A 10g sample of a radioactive isotope has a half-life of 3 days. Match the correct fraction that remains unchanged after the given amount of mass

• 1/2 radioactive

• 1.25 grams

• 1/16 radioactive

• 5 grams

• 1/4 radioactive

• 0.625 grams

• Completely radioactive

• 2.5 grams

• 1/8 radioactive

• 10 grams

Ge-81 emits beta particles and has a half-life of 7.6 seconds.

Determine the time required for a 16.00-gram sample of Ge-81 to decay until only 1.00 gram of the sample remains unchanged.

• 1/16 radioactive

• 16 grams

• 1/8 radioactive

• 4 grams

• Completely radioactive

• 1 grams

• 1/2 radioactive

• 2 grams

• 1/4 radioactive

• 8 grams

Ge-81 emits beta particles and has a half-life of 7.6 seconds.

Determine the time required for a 16.00-gram sample of Ge-81 to decay until only 1.00 gram of the sample remains unchanged.

• 2 half - lives and 15.2 seconds

• 16 grams

• 4 half -lives and 30.4 seconds

• 2 grams

• 1 half life and 7.6 seconds

• 8 grams

• 3 half lives and 22.6 seconds

• 1 grams

• 0 half lives and no time

• 4 grams

The ratio of the mass of U-238 to the mass of Pb-206 can be used to

• 
  diagnose thyroid disorders

• diagnose kidney function

• date geological formations

• date once-living things

The ratio of the mass of C-14 to the mass of N-14 can be used to

• 
  diagnose thyroid disorders

• diagnose kidney function

• date geological formations

• date once-living things

Which risk is related to the radioactive isotopes used to generate electricity?

• biological exposure

• curing of diseases

• industrial measurements

• tracing chemical processes