Half Life Measurement Multiple Choice Questions with Answers – PDF Download

MCQ 1: If a C-14 has a half-life of 5730 years, then how long will it take for the number of C-14 in a sample to drop to 1/8 of initial quantity?

1. 2.58 × 10⁴ years
2. 1.44 × 10⁴ years
3. 1.72 × 10⁴ years
4. 2.58 × 10⁴ years

MCQ 2: If a radioactive element has a half-life of 40 minutes. The initial count rate was 1000 per minute, then how long will it take for the count rate to drop to 125 per minutes:

1. 120 minutes
2. 90 minutes
3. 30 minutes
4. 60 minutes

MCQ 3: What fraction of the original sample will be after 22 years, if the Cobalt-50 is a radioactive element with a half-life of 4.3 years?

1. 1 ⁄ 32
2. 1 ⁄ 16
3. 1 ⁄ 8
4. 1 ⁄ 4

MCQ 4: If the activity of a sample of radioactive bismuth decreases to 1/8 of its original activity in 15 days, then the sample's half-life will be:

1. 3 days
2. 10 days
3. 5 days
4. 7 days

MCQ 5: Radium-226 has a half-life of:

1. 1160 years
2. 1340 years
3. 1580 years
4. 1620 years