|
|
QUESTIONS ON RADIOACTIVITY (HIGHER LEVEL)
|
|
|
Use the radioactivity website to answer the questions below: |
|
1. |
In Rutherford's experiment why did he think all particles would pass through the foil? |
|
2. |
Explain why Rutherford came to the conclusions he did about the structure of an atom. |
|
3. |
What are the charges of protons, neutrons and electrons? |
|
4. |
In an atom where are the electrons? |
|
5. |
What are the relative masses of protons, neutrons and electrons? |
|
6. |
Define the atomic, neutron and mass number of an atom. |
|
7. |
What is the mass number of Lithium? |
|
8. |
If the atomic number of Lithium is 3, how many neutrons are in the nucleus? |
|
9. |
What do all isotopes have in common? |
|
10. |
What differs from one isotope to another? |
|
11. |
What is a radioisotope? |
|
12. |
Explain what radioactivity means. |
|
13. |
State the 3 ways radioisotopes can lose energy and 3 characteristics of each type. |
|
14. |
What has to happen in the nucleus of an atom before a beta particle can be emitted? |
|
15. |
Give an approximate value for the wavelength of gamma radiation. |
|
16. |
Explain what the term ionisation means. |
|
17. |
Write down in order (highest to lowest) the ionising power of alpha, beta and gamma. |
|
18. |
From your answer to question 17 write down in the same order their penetrating powers. |
|
19. |
Why are beta particles deflected most by an electric field? |
|
20. |
How many neutrons are in a nucleus of Carbon-14 if the atomic number is 6? |
|
21. |
Explain how a Geiger Muller tube detects radiation. |
|
22. |
Write down the different sources of background radiation. |
|
23. |
What is the biggest contributor to background radiation? |
|
24. |
Explain the term decay of a radioisotope. |
|
25. |
State the unit of radioactivity. |
|
27. |
If a radioactive sample has an activity of 25 Bq how many nuclei decay each minute? |
|
28. |
Define the term half-life. |
|
29. |
What is the half-life of Uranium-235? How many neutrons does Uranium-235 have? |
|
30. |
What dose level of radiation can lead to cancer? |
|
31. |
Explain why alpha particles are not as dangerous outside the body. |
|
32. |
Which radiation types are the most dangerous inside the body? Explain why. |
|
33. |
Name two radioisotopes commonly used in medicine. Explain why they are used. |
|
34. |
Explain how a beta source can be used to determine the thickness of paper. |
|
35. |
Explain why Americium-241 is used in smoke detectors. |
|
36. |
Which two isotopes are formed in the fission of Uranium when 3 neutrons are emitted. |
|
37. |
Explain what the term chain reaction means. |
|
38. |
Which process gives the most energy, fission or chemical bond formation. |
|
39. |
How does a nuclear power plant work? |
|
40. |
What are the advantages and disadvantages of nuclear power? |
|
41. |
What is meant by the decay series of Uranium-238? |
|
42. |
How old is an igneous rock with a Uranium-238:stable Lead ratio of 1:7? |
|
43. |
The Turin Shroud was estimated to be 600 years old. What is the C-14:N-14 ratio? |
|
44. |
What do you think neutron capture means? |
|
45. |
How many electrons orbit a neutral atom of Manganese-55 (atomic number 25)? |
|
46. |
If the initial activity of a sample of rock has fallen to 1/8 how old is the rock? |
|
47. |
Calculate the age of a rock with a U-235:stable Lead ratio of 1:3 |
|
48. |
Explain the significance of the numbers 235 and 92 for an atom of Uranium. Uranium-236 atoms are unstable and disintegrate spontaneously into fragments around the same size, together with two or three fast-moving neutrons and a large amount of energy. What is this process called and what is the source of the energy? |
|
49. |
Some rocks contain the radioisotope Uranium-235 that has a half-life of 700 million years. It eventually decays into Lead-207. On graph paper draw a decay curve for Uranium-235 showing the proportion of U-235 remaining (range 0-1.0) against time (0 - 2500 million years). Samples of an igneous rock gave an average ratio of 70 atoms of U-235 to 30 atoms of Pb-207. Use the decay curve you have drawn to estimate the age of the rock. |
|
50. |
A scientist wanted to find out the age of a sample of rock. The isotope Potassium-40, present in many rocks, slowly undergoes radioactive decay to form Argon-40. When the rock was formed the Potassium-40 isotope was trapped in the rock and there was no Argon-40. All the Argon-40 formed by the Potassium-40 decay also stayed trapped in the rock. The scientist found that the rock contained 3 times more Argon-40 than Potassium-40. What fraction of the original Potassium-40 is left in the rock? The half-life of Potassium-40 is 1400 million years. Calculate the age of the rock. |
|
Questions 48, 49 and 50 are past NEAB exam paper questions. |
|
|
|
|
|
VIEW CONTENTS |
