Nuclear Chemistry Exam Prep Notes

Radioisotope Stability

  • Sample elements that are already active must be unstable.
  • To study blocks, choose elements with long half-lives, like Uranium-238.
  • Half-life information can be found in Table N.

Radioisotopes in Chemical Reactions

  • Radioisotopes can trace the course of a chemical reaction.
  • Radioisotopes emit energy, allowing the tracing of reaction mechanisms or processes.
  • Each step of the chemical process can be followed using radioisotopes.

Bombarding and Artificial Transmutation

  • "Bombarding" means hitting a nucleus with high-energy particles.
  • Bombarding a nucleus with high-energy particles to change it from one element to another is called artificial transmutation.
  • Natural transmutation: one reactant.
  • Artificial transmutation: two or more reactants.

Fusion Reactions

  • Fusion reactions are difficult to initiate because the charge of the nucleus is positive.
  • Like charges repel each other, making it hard for two positive nuclei to come together.
  • High temperature and high pressure are required for fusion, which naturally occurs in stars like the sun.

Artificial Transmutation

  • A reaction where an element is smashed with an alpha particle to change it is artificial transmutation.
  • Artificial transmutation typically starts with two or more reactants.

Balancing Nuclear Equations

  • Example: Iodine-131 undergoes beta decay.
  • To balance any nuclear reaction or equation, balance the mass and balance the charge.

Energy Release

  • Fission releases the greatest amount of energy per gram.

Identifying Artificial Transmutation

  • Artificial transmutation involves two or more reactants.

Charges of Particles

  • Group two has all charges.

Mass-Energy Conversion

  • Currently, we can convert mass to energy, but not energy to mass.

Penetrating Power

  • Order of penetrating power (greatest to least): gamma, alpha particles

Half-Life Calculations

  • Use a T-chart to solve half-life problems.
  • Given: 6 mg of a sample is left after 7.36 seconds.
  • Half-life: 1.84 seconds.
  • Goal: Find the original mass.
  • Start with time = 0.
  • After one half-life (1.84 seconds).
  • Continue until you reach 7.36 seconds.