45. NUCLEAR MEDICINE: SPONTANEOUS FISSION

Question 1

1. How can nuclei with very large atomic mass numbers disintegrate?

Answer 1

• they can split into two nearly equal fission fragments
• this usually happens to nuclei that have atomic masses
  greater than 92

Question 2

2. What does Spontaneous Fission (SF) result in?

Answer 2

• the spontaneous emission of 2-4 neutrons
• there is a significant amount of energy released

Question 3

3. What kind of process does Spontaneous Fission follow?

Answer 3

• the same process as Neutron-induced Nuclear fission
• Spontaneous Fission is not self-sustaining
• it occurs in Radioactive Nuclei

Question 4

4. List 4 elements that experience Spontaneous Fission?

Answer 4

1. Thorium
2. Protactinium
3. Uranium
4. Transuranic Elements
   (these are the elements higher than Uranium)
   ( they have an atomic number greater than 92)

Question 5

5. What kinds of elements are Transuranic Elements?

Answer 5

• they are man-made
• they are synthesised in Nuclear Reactions

Question 6

6. What process does Spontaneous Fission compete with?

Answer 6

• Alpha Decay

Question 7

7. What happens to elements that have an atomic mass number above Uranium (A=238)?

Answer 7

THE HIGHER THIS ATOMIC MASS NUMBER:
- the more prominent the Spontaneous Fission
- the shorter the half life

Question 8

8. How does Spontaneous Fission act as a limiting factor?

Answer 8

IT ACTS AS A LIMITING FACTOR:
- in how high the atomic number of an element can go
- in how high the atomic mass number can go
- in terms of producing new elements