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Constructed Response . Topic 12: Nuclear Chemistry

Set A: Nuclear equation, half-life

Base your answers to questions 1 and 2 on the information below.

Uranium-238, a solid, is a naturally radioactive element found in the earth’s crust.
As it decays one of the products is radon-222, which is a gas and is very radioactive.

1. Write a nuclear equation for the decay of Rn-222. 1.

2. The half-life of Radon-222 is 3.82 days. How many 2.

grams of a 1.0 gram sample of radon-222 would

remain after 7.64 days?

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Set B: Balancing nuclear equation

Given the equation below:

58
58

Cu ---------- > Ni + X
29 28

3. What nuclear particle is represented by X? 3.

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Set C: Radioactive dating, balancing nuclear equation, half-life

Base your answers to questions 4 through 6 on the information below.

The radioisotopes carbon-14 and nitrogen-16 are present in a living organism.
Carbon-14 is commonly used to date once-living organisms.

4. Explain why N-16 is a poor choice for radioactive 4.

dating of a bone.

0
14
5. Complete the nuclear equation for the decay 5. C -------- > e + _______
6 -1

of C-14. Include both the atomic number and

the mass number of the missing particle.

1
6. A sample of wood is found to contain /8 as much 6.

C-14 as is present in the wood of a living tree.

What is the age, in years, of this sample of wood?

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