MCQ on Half-Life with Answers:
1. What is half-life?
a) The time it takes for a substance to decay to half its initial mass
b) The time it takes for a substance to decay completely
c) The time it takes for a substance to reach its maximum decay rate
d) The time it takes for a substance to stabilize its decay rate
2. Which of the following factors does not affect the half-life of a substance?
a) The initial amount of the substance
b) The type of decay involved
c) The temperature of the substance
d) The presence of other substances
3. If a radioactive substance has a half-life of 10 days, how much of the substance will remain after 20 days?
4. If a sample of radioactive material has a half-life of 5 hours and initially contains 100 grams of the substance, how much of the substance will remain after 15 hours?
a) 12.5 grams
b) 25 grams
c) 50 grams
d) 75 grams
5. Which of the following types of decay is most commonly associated with alpha particles?
a) Gamma decay
b) Beta decay
c) Positron emission
d) Alpha decay
6. The half-life of a substance is 8 days. If there are initially 1000 atoms of the substance, how many atoms will be left after 24 days?
a) 125 atoms
b) 250 atoms
c) 62.5 atoms
d) 500 atoms
7. Which of the following is not a unit used to express half-life?
8. Which of the following isotopes has the longest half-life?
9. Which of the following statements about half-life is true?
a) Half-life is a constant value for all substances
b) Half-life can be used to predict exactly when a substance will decay
c) Half-life is an exponential process
d) Half-life is only applicable to radioactive substances
10. Which of the following statements about half-life is false?
a) Half-life can be used to determine the age of ancient artifacts
b) Half-life can be used to calculate the amount of radioactive substance remaining after a certain period of time
c) Half-life is a measure of how fast a substance decays
d) Half-life is not affected by external factors such as temperature or pressure