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Chapter 5 - Nuclear Chemistry

5.1 - Natural Radioactivity

  • Radioactive isotopes are characterized as unstable nucles (decay), alpha (a), beta (b), positron (b+), gamma (g) radiation spontaneous radiation
  • Radiation can damage the cells in the body and it is important to use the right protection: shielding, exposure time limit and distance.

5.2 - Nuclear Reactions

  • The changes in the nuclei of reactants and products are represented by a balanced nuclear equation

  • A number of symbols that display the mass and nuclear number of the isotopes in the nuclear equation can help determine the new isotopes and the type of radiation emitted.

  • When a small particle bombards a non-radioactive isotope, a radioisotope is produced artificially.

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5.3 - Radiation Measurement

  • Radiation produces charged particles in the gas in a tube that generates an electric current in a Geiger counter.
  • The curie (Ci) and the becquerel (Bq) measure the number of nuclear transformations per second. the activity is measured.
  • A radical or gray measure of the amount of radiation absorbed by a substance (Gy).
  • The rem and sievert (Sv) are units for the determination of the different radiation types of biological damage.

5.4 - Half-Life of a Radioisotope

  • Each radioisotope has its own emission rate.
    • It's called half-life the time it takes for half of a radioactive sample to decline.
  • Half-life is short for many medical radioisotopes, including Tc-99m and TC-1,
    • Half-lives are extremely long for other isotopes, typically occurring naturally, like C-14, Ra-226, and U-238.

5.5 - Medical Applications Using Radioactivity

  • Radioisotopes that visit certain sites within the body are administered to the patient in nuclear medicine.
  • By detecting the radiation that they emit, the size and scope of an injury, disease, tumor, or function level of a certain organ can be assessed.
    • Higher radiation levels are used for tumor treatment or destruction.

5.6 - Nuclear Fission and Fusion

  • In fission, the bombing of a large nucleus divides into smaller nuclei and releases a large amount of energy and one or more types of radiation.
    • Infusion, small nuclei form larger nuclei and release large amounts of energy.