Nuclear Half Life and Reactions

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?

• 100.0g
• 50.0g
• 12.5g
• 8.5g

After the third half-life, how much of the sample is left?

• 1/2
• 1/3
• 1/16
• 1/8

Tags

NGSS.HS-PS1-8

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

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

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

After 22,800 years, approximately what percentage of the original carbon-14 remains?

• 15%

• 12.5%

• 6.25%

• 3.125%

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

Tags

NGSS.HS-PS1-8

Finish this equation

²⁰⁹₈₃Bi--> _{_______ +} ²⁰⁵₈₁Tl

• ⁴₂He

• ⁰_-1e

• y

Tags

NGSS.HS-PS1-8

The most dangerous type of radiation is the ____. 

• alpha particle
• gamma ray
• beta particle
• uranium

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

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

Tags

NGSS.HS-PS1-8

Identify the missing substance in each of the following nuclear reaction.

_____→¹³⁷₅₆ Ba + ⁰₋₁ e

• ¹³⁷₅₅Ba

• ¹³⁷₅₇La

• ¹³⁸₅₆Ba

• ¹³⁷₅₅Cs

Tags

NGSS.HS-PS1-8