# The half-life of carbon-14 is 5,730 years. If you started with 100.0 g of carbon-14, how much would remain after…

Example: The half-life of carbon-14 is 5,730 years. If you started with 100.0 g of carbon-14, how much would remain after 4 half-lives? Please explain how you got the answer.

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mendez (mmm5697) – Half Life – cartas – (12621302) 1

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001 10.0 points

What does NOT describe a nuclear reaction?

1. Reaction rate is not influenced by external
factors.

2. All of these correctly describe a nuclear
reaction.

3. Relatively small amounts of energy are
released or absorbed.

4. Elements may be converted from one to
another.

5. Particles in the nucleus are involved.

002 10.0 points

The half-life of 137Ce is 30 years. How many
grams of 137Ce must be produced now to have
a sample containing 32 g of 137Ce 140 years
from now?

003 10.0 points

The half-life of 222Rn is 3.82 days. If we have
62 g of 222Rn how many grams will be left
after 10 half-lives?

004 10.0 points

The half life of thallium-201 is 21.5 hours. We
have 88 g of thallium-201 how many grams
will be left after 10 half-lives?

005 10.0 points

The half-life of carbon-14 is 5,730 years. If
you started with 100.0 g of carbon-14, how
much would remain after 4 half-lives?

1. 12.5 g

2. 6.25 g

3. 25.0 g

4. 57.3 g

006 10.0 points
239Pu has a half-life of 24000 years. If we have
10 g of 239Pu, how many grams will be left
after 38000 years?