Chem Unit 9 Review

Which best represents nuclear fission?

• F

• G

• H

• J

If 10 mg of iodine 131 is given to a patient, how much is left after 24 days? The half-life of iodine-131 is 8 days.

• 1.25mg
• 1.25g
• 10g
• 10mg

The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?

• 3.0g
• 0.25mg
• 0.3g
• 0.25g

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%

After 4 half-lives, 1g of a sample of Krypton-85 remains unchanged.  What was the original mass of the sample?

• 16g
• 32g
• 0.0625g
• 4g

How is the alpha particle written in a nuclear equation?

• ⁴₂He

• ²₄He

• ⁰_-1e

• ⁰₀γ

Which type of nuclear radiation is being emitted here?

• Alpha
• beta
• gamma 
• none

Solve this equation for alpha decay.
₈₅²⁰⁹At = ___ + ₂⁴He

• ₈₃²⁰⁵Bi
• ₈₆²⁰⁹Rn
• ₈₁²⁰⁷Tl
• ₈₅²⁰⁸At

Solve this equation for beta decay.
₆¹⁴C = ___ + _-1⁰e

• ₄¹⁰Be
• ₇¹⁴N
• ₂¹⁰He
• ₆¹³C