Half Life Quiz

A 180-gram sample of radium undergoes radioactive decay. After 5 half-lives, how much mass remains? Show the simple halving process in your reasoning.

• 5.625 g

• 9 g

• 11.25 g

• 22.5 g

A 75-gram sample of radium decays for 3 half-lives. How much radium remains?

• 9.375 g

• 18.75 g

• 25.0 g

• 37.5 g

A 350-gram sample of radium decays through 4 half-lives. How many grams are left?

• 21.875 g

• 43.75 g

• 87.5 g

• 175 g

An 80-gram sample of radium decays for 5 half-lives. Determine the remaining mass.

• 2.5 g

• 5 g

• 10 g

• 20 g

A 654-gram sample of radium experiences 3 half-lives. Calculate the mass that remains.

• 81.75 g

• 163.5 g

• 327 g

• 436 g

Titanium has a half-life of 10 days. If the initial mass is 650 grams, how much titanium remains after 30 days?

• 81.25 g

• 162.5 g

• 325 g

• 433 g

Titanium has a half-life of 10 days. Starting with 650 grams, how much titanium remains after 50 days?

• 20.3125 g

• 40.625 g

• 65.0 g

• 130.0 g

Titanium has a half-life of 5 days. If the initial mass is 820 grams, how much titanium remains after 20 days?

• 51.25 g

• 102.5 g

• 205 g

• 410 g

Titanium has a half-life of 5 days. If the initial mass is 820 grams, how much titanium remains after 30 days?

• 12.8125 g

• 25.625 g

• 51.25 g

• 102.5 g

A 660-gram sample of copper decays to 20.625 grams. If one half-life is 2 years, how long did the decay take? Choose the best time.

• 6 years

• 8 years

• 10 years

• 12 years