Half Life Notes

Multiple Choice

_______________ is the process by which unstable atoms emit radiation until they become stable.

• Radiation

• Chemical Reaction

• Radioactive Decay

• Isotopes

Multiple Choice

What is Half-life?

• The amount of time it takes for some of the nuclei in a sample of the isotope to decay

• The amount of time it takes for half the electrons in a sample of the isotope to decay

• The amount of time it takes for half the nuclei in a sample of the isotope to decay

• the amount of time it takes to double the nuclei in a sample of the isotope to decay

Multiple Choice

The Half Life of Californium 252 is 5 years.

• TRUE

• FALSE

Multiple Choice

What is the Half Life of this isotope?

• 3 days

• 5 days

• 8 days

• 10 days

Multiple Choice

What is the half life of californium?

• 1 year

• 2.8 years

• 3 years

• 5 years

Multiple Choice

If the half life of a radioactive element is 100yrs, how long would it take for the radioactivity to reduce by one half?

• 200yrs

• 100yrs

• 50yrs

• 300yrs

Multiple Choice

A certain radioactive sample has a half life of 2 years. After 6 years, how much of the sample is left?

• 1/2

• 1/3

• 1/16

• 1/8

Multiple Choice

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 2.4 minutes has elapsed?

• 100.0g

• 50.0g

• 12.5g

• 8.5g

Multiple Choice

After the third half-life, how much of the sample is left?

• 1/2

• 1/3

• 1/16

• 1/8

Multiple Choice

If 10 mg of iodine 131 is given to a patient, how much is left after 8 days? The half-life of iodine-131 is 8 days.

• 5.0mg

• 1.25g

• 10g

• 10mg

Multiple Choice

What is the half-life of iodine-131?

• 32 days

• 8 days

• 16 days

• 24 days