Radioactive Decay

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

• 1/2
• 1/3
• 1/16
• 1/8

If 10 mg of iodine 131 is given to a patient, how much is left after 24 days? The half-life of iodine-131 is 8 days.

• 1.25mg
• 1.25g
• 10g
• 10mg

You have 100 grams of radioactive C-14. The half life of C-14 is 5730 years. 
How many grams are left after 1 half life? 

• 100 grams
• 25 grams
• 2 grams
• 50 grams

What is the symbol for an alpha particle?

• ⁴₂He
• ⁰_-1e
• ⁰₊₁ e
• ¹₀n

What is the Half Life of this isotope?

• 3 days

• 5 days

• 8 days

• 10 days

The Half Life of Californium 252 is 5 years.

• TRUE

• FALSE

The time it takes for a radioactivity level to drop by a half is is the sample's ___________________.

• quarter life

• whole life

• wonderful life

• half life

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

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

• Radiation
• Chemical Reaction
• Radioactive Decay
• Isotopes

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