| 1. | Which of the following should be kept in a container made of disintegrative (radioactive) items? |
A. Pb | |
B. Steel | |
C. Fe | |
D. AI |
| 2. | What is the change in atomic number and atomic mass due to emission of a β particle? |
A. Atomic number increased by 1 and atomic mass remained unchanged | |
B. Atomic number decreased by 1 and atomic mass remained unchanged | |
C. Atomic number unchanged and atomic mass increased by 1 | |
D. Atomic number unchanged and atomic mass decreased by 1 |
| 3. | What will be the change in atomic number and atomic mass due to the emission of an α particle? |
A. Atomic number increased by 1 and atomic mass remained unchanged | |
B. Atomic number decreased by 1 and atomic mass remained unchanged | |
C. Decrease in atomic number by 2 and increase in atomic mass by 4 | |
D. Decrease in atomic number by 2 and decrease in atomic mass by 4 |
| 4. | The substance formed after 1 β emission from ₁₁Na² is |
A. Mg | |
B. Mn | |
C. Ag | |
D. Pb |
| 5. | How many α and β particles will be emitted in ₉₂U²³⁶ → ₈₇U²²⁴? |
A. 3a, 5b | |
B. 3a, 4b | |
C. 7a, 3b | |
D. 3a, 1b |
| 6. | If the amount of a radioactive substance is doubled, then the rate of radioactive decay – |
A. remains unchanged | |
B. remains half | |
C. triples | |
D. doubles up |
| 7. | If ₉₂U²³⁸ decays to form ₉₁Pa²³⁴ then how many α and β particles are emitted? |
A. 1α and 1β | |
B. 2α and 2β | |
C. 1α and 2β | |
D. 2α and 1β |
| 8. | The lifetime of a radioactive substance is 70 days, then after how many days one gram of the same substance will be reduced to 0.25 grams |
A. 140 days | |
B. 70 days | |
C. 210 days | |
D. 280 days |
| 9. | If the half-life period of a radioactive substance is one day, then after 4 days what part of its initial quantity will be left? |
A. 12½ % | |
B. 26¼ % | |
C. 6¼ % | |
D. 16 ¼% |
| 10. | The half-life of a radioactive substance is four months, the time taken for three-fourths of the substance to decay is |
A. 3 months | |
B. 4 month | |
C. 8 months | |
D. 12 months |