ICP - Quick Review half life

If 131 mg of iodine-140 is given to a patient, and after 24 days there are 16.375 mg of iodine-140 remaining. How many half lives have passed?

• 1

• 2

• 3

• 4

The half-life of strontium-90 is 25 years. The original sample contained 4.0 g and later on the sample is observed to contain only 0.25 g. How many half lives have passed?

• 1

• 2

• 3

• 4

If the half-life of uranium-232 is 70 years, how many half-lives will it take for 10 g of it to be reduced to 1.25 g?

• 1 half-life

• 2 half-lives

• 3 half-lives

• 4 half-lives

The % of the parent isotope remaining after 1 Half Life.

• 50%

• 25%

• 12.5%

• 6.25%

Tags

NGSS.HS-PS1-8

The % of the parent isotope remaining after 2 Half Lives.

• 50%

• 25%

• 12.5%

• 6.25%

Tags

NGSS.HS-PS1-8

You have 100 grams of radioactive C-14. The half life of C-14 is 5, 730 years.

How many grams are left after 11,460 years?

• 100 grams

• 25 grams

• 2 grams

• 50 grams

It took 75 years for an original sample of 4.0 g of strontium-90 to decay to only 0.5 g. How long is the half life of strontium-90?

• 25 years

• 37.5 years

• 21 years

• 30 years

It took 210 years for a sample of uranium-232 to decay from 10 g to 1.25 g. How long is a half life of uranium-232?

• 70 years

• 8 years

• 185.6 years

• 77.33 years

A fresh sample of Barium-122 weighing 80 g was obtained. After only 10 minutes, there are 2.5 g of Barium-122 remaining. How long is a half life of Barium-122?

• 2 minutes

• 16 minutes

• 48.8 minutes

• 8 minutes

If 10 mg of iodine 131 is given to a patient, how much is left after 32 days? The half-life of iodine-131 is 8 days.

• 1.25mg

• 0.3125mg

• 2.5mg

• 0.625mg

Tags

NGSS.HS-PS1-8