Half-life calculations
10th grade (Year 11 in England) · 16 questions · Common Core: NGSS.HS-PS1-8, NGSS.SEP 5 · England: GCSE Combined Science: Atomic structure (radioactivity) (half-lives)
Name
Date
Score/ 16
Question 1
The count rate of a radioactive source falls from 1200 counts/min to 150 counts/min in 30 minutes. What is its half-life, in minutes?
Answermin
Question 2
A sample contains 12800 undecayed nuclei. How many remain undecayed after 4 half-lives?
Answer
Question 3
A sample has an activity of 800 Bq. Its half-life is 8 days. What is its activity after 8 days, in Bq?
AnswerBq
Question 4
The count rate of a radioactive source falls from 640 counts/min to 320 counts/min in 3 minutes. What is its half-life, in minutes?
Answermin
Question 5
A sample contains 3200 undecayed nuclei. How many remain undecayed after 3 half-lives?
Answer
Question 6
A sample has an activity of 800 Bq. Its half-life is 12 days. What is its activity after 12 days, in Bq?
AnswerBq
Question 7
The count rate of a radioactive source falls from 640 counts/min to 80 counts/min in 9 minutes. What is its half-life, in minutes?
Answermin
Question 8
A sample contains 1600 undecayed nuclei. How many remain undecayed after 2 half-lives?
Answer
Question 9
A sample has an activity of 1200 Bq. Its half-life is 6 minutes. What is its activity after 18 minutes, in Bq?
AnswerBq
Question 10
The count rate of a radioactive source falls from 1200 counts/min to 300 counts/min in 20 minutes. What is its half-life, in minutes?
Answermin
Question 11
A sample contains 6400 undecayed nuclei. How many remain undecayed after 4 half-lives?
Answer
Question 12
A sample has an activity of 400 Bq. Its half-life is 8 hours. What is its activity after 32 hours, in Bq?
AnswerBq
Question 13
The count rate of a radioactive source falls from 1200 counts/min to 300 counts/min in 8 minutes. What is its half-life, in minutes?
Answermin
Question 14
A sample contains 1600 undecayed nuclei. How many remain undecayed after 2 half-lives?
Answer
Question 15
A sample has an activity of 1600 Bq. Its half-life is 5 hours. What is its activity after 20 hours, in Bq?
AnswerBq
Question 16
The count rate of a radioactive source falls from 960 counts/min to 240 counts/min in 8 minutes. What is its half-life, in minutes?
Answermin
Write your answers right on the page. · Free from eurekami.com