Half Life

If I have a sample of Carbon-14 with 12.5% of its original amount of radioactive material, how many half-lives have elapsed?

Tags

NGSS.HS-PS1-8

The radioactive isotope Nickel-63 has a half-life of 100 years. How much would remain of a 10 gram sample after 400 years?

Tags

NGSS.HS-PS1-8

How long will it take a sample of Polonium-194 to decay to 1/8 of its original amount, if it has a half-life of 0.7 seconds?

Tags

NGSS.HS-PS1-8

Astatine-218 has a half-life of 1.6 seconds. Suppose you have a 1.2 gram sample of Astatine-218. How much would remain after 6.4 seconds?

Tags

NGSS.HS-PS1-8

Thorium-234 has a half-life of 24 days. How much would remain after 72 days if you started with 100 grams?

Tags

NGSS.HS-PS1-8

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

Tags

NGSS.HS-PS1-8

The time required for half of the nuclei of an isotope to decay.

• Half-life

• radioactive dating

• critical mass

• critical point

Tags

NGSS.HS-PS1-8

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

Tags

NGSS.HS-PS1-8

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

Tags

NGSS.HS-PS1-8

If one-fourth of the carbon-14 is remaining then how many half-lives have passed?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-8