Problem set 1
Chart of the Nuclides
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Make a table from the chart of nuclides that explains what the different colors stand for.
The Chart of nuclides is organized with number of neutrons along the x axis and number of protons along the y axis. Explain the following terms and how to find them in the map. Use 28Si as a point of reference and give examples of the following:
Use the chart of nuclides to find the heaviest naturally occurring element (the half-life must be longer than the age of the earth).
Find the heaviest stable nuclide.
Check the following about the element Ar:
- Which stable isotope of Ar is the most abundant?
- Which radioactive isotope of Ar has the longest half-life?
- List the different Ar isotopes that have half-lives with seconds as order of magnitude.
- What is the energy of the γ-radiation emitted when 43Ar disintegrates and which is the most intense?
6: Find information about the following from the char of nuclides:
- What kind of information is given in the square for stable nuclides?
- If a nuclide emits β-radiations how is it possible to determine the type of β-radiation and its strength? Which unit is used to describe the energy?
- When a nuclide disintegrates is it possible to determine whether or not it will emit γ-radiation? If so, what unit is used to describe the energy?
Which radioactive isotope of Si has the longest half-life, and how will it disintegrate until it reaches stability?
A radionuclide unable to form by disintegration of another radionuclide is said to be shielded. The element Promethium (Pm, Z=61) has no stable isotopes. Find the isotope with the longest half-life and make a disintegration chain until stability. Are any of the Pm isotopes shielded?
9: Some radionuclides compete between β+ and β- disintegration, where are these located?
10: List the most likely decay chains from 179Hg until it reaches stability.
In the chart of nuclides the isomeric state (m) is listed on the left side of the square, while the ground state (g) is listed on the right side. For those cases that are characterized, m and g describes which state the decay of the mother will primarily lead to. In regards to this, list the chain of disintegration from 121Ag until stability.
Some nuclides have a square divided with several colours. Use 211Ra and 214Ra to explain what this means (hint; check the explanation to the chart of nuclides).
13: List the disintegration chain from a nucleus of 232Th until stability (branching of 5% and less intensity can be ignored).
A pure, freshly produced thorium salt with 232Th as the only thorium isotope will not emit any γ-radiation, but an old thorium salt will emit strong high energetic γ-radiation. Explain why this occurs and specify the amount of energy on the radiation.
15: Neutron poor nuclides may disintegrate with both β+ and EC and close to stability only EC is possible. List the disintegration of 201Tl and 197Tl. What kind of radiation is emitted in each of these cases?