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Grade 12 Radioactivity & Half-Life Worksheet with Answers
Grade 12 (US) · Year 13 (UK) · Class 12 (India) · Chemistry
Unit 4: Nuclear ChemistryHalf-LifeNGSS HS-PS1-8
Calculating how much of a radioactive sample remains, and dating with half-lives. This free high school worksheet has 12 questions and a full answer key. Print it or save it as a PDF — every answer is checked by code, not guessed.
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Practice Sheetaethelsystems.comRadioactivity & Half-Life
Grade 12 · Chemistry
Name
Class
Date
Learning goal: Half-Life · NGSS HS-PS1-8
Directions: Read each question carefully and write your answer on the line. Use the diagram to help you.
A 320 g sample has a half-life of 8 days. How much remains after 8 days?
Answer: 160 g
RememberHalf-life
- 1
A sample with a half-life of 20 days drops from 640 g to 160 g. How much time has passed?
- 2
A sample with a half-life of 30 days drops from 320 g to 160 g. How much time has passed?
- 3
A sample with a half-life of 5730 years drops from 200 g to 50 g. How much time has passed?
- 4
A sample with a half-life of 5730 years drops from 1000 g to 500 g. How much time has passed?
- 5
A sample with a half-life of 5 days drops from 160 g to 20 g. How much time has passed?
- 6
A sample with a half-life of 10 days drops from 1000 g to 500 g. How much time has passed?
- 7
A sample with a half-life of 5 days drops from 200 g to 50 g. How much time has passed?
- 8
A sample with a half-life of 20 days drops from 80 g to 20 g. How much time has passed?
- 9
A 160 g sample has a half-life of 8 days. How much remains after 16 days?
- 10
A sample with a half-life of 5730 years drops from 160 g to 40 g. How much time has passed?
- 11
A 160 g sample has a half-life of 30 days. How much remains after 30 days?
- 12
A 200 g sample has a half-life of 10 days. How much remains after 20 days?
★ Challenge corner for fast finishers
You are in a closed room with a candle, a match and a lamp. What do you light first?
How did I do?
Teacher's comments
Free printable worksheets with answer keys · aethelsystems.com/worksheets/chemistry/12/half_life
Answer key — Radioactivity & Half-Life (Grade 12)
- 1.40 days
- 2.30 days
- 3.11,460 years
- 4.5,730 years
- 5.15 days
- 6.10 days
- 7.10 days
- 8.40 days
- 9.40 g
- 10.11,460 years
- 11.80 g
- 12.50 g
- ★the match
Answer key (click to show)
- 1.40 days
- 2.30 days
- 3.11,460 years
- 4.5,730 years
- 5.15 days
- 6.10 days
- 7.10 days
- 8.40 days
- 9.40 g
- 10.11,460 years
- 11.80 g
- 12.50 g
- ★the match (challenge corner)
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