Summary of Radioactivity & Nuclear Medicine

00:00:00 - 00:35:00

This video discusses the work of Marie Curie and the discovery of radioactivity. It explains how radiation works and how various types of radiation behave. The video also covers the discovery of the proton and neutron, which were key to understanding the behavior of radiation.

• 00:00:00 In 1896, physicist Henri Becquerel discovered radiation, which he named "x-rays." Scientists had been aware of the phenomenon of phosphorescence in certain salts of uranium for some time, but Becquerel's experiments were the first to identify radiation as the cause. Becker L. observed that x-rays emitted from uranium crystals reduced silver salts, and he was certain that the observed phenomenon was the result of uranium crystals absorbing energy from the Sun and re-emitting it as x-rays. However, when he attempted to repeat his experiment a few days later, bad weather interfered.
• 00:05:00 Marie Sklodowska Curie was a Polish physicist and chemist who, with her husband Pierre Curie, discovered the element uranium. In 1896, Becker L. announced his discovery of uranium waves. Almost a year later, Curie felt that this would be a topic worthy of investigation and began looking for a research topic. In 1897, her husband discovered the piezoelectric effect. As fate would have it, Marie's husband was already a well-known scientist in Paris. With their father, they had discovered the piezoelectric effect 17 years earlier. Using the electrometer, they were able to accurately measure electrical potential. In 1880, the brothers would not have had access to a modern-day voltmeter.
• 00:10:00 This video and accompanying transcript discuss the work of Marie Curie, who discovered two new elements - polonium and radium - in the early 20th century. Marie Curie's laboratory consisted of a variety of equipment, some of which is still in use. One of Marie Curie's main instruments was a quadrant electrometer, which was used to measure the electrical properties of various substances. In addition to her work in the laboratory, Marie Curie also developed radioactivity, which was instrumental in the discovery of the radioactive elements polonium and radium.
• 00:15:00 This video explains how radiation works and how various types of radiation, such as x-rays, alpha radiation, and beta radiation, behave. It also covers the discovery of the proton and neutron, which were key to understanding the behavior of radiation.
• 00:20:00 The video demonstrates the phenomenon of ionizing radiation, which is the result of the x-ray emitting radiation passing through the air gap between the front terminals. When the x-ray is a form of ionizing radiation similar to gamma rays, they can knock away some of the orbiting electrons around the nuclei of the oxygen nitrogen and other gases in the air, turning them into positively charged ions. This is the same phenomenon that Madame Curie noted in her 1897 and 1898 experiments.
• 00:25:00 In nuclear physics, beta decay is a type of radioactive decay in which an electron is released. The small electron is negatively charged, and this causes the decay to be referred to as beta minus decay. The difference between beta minus and beta decay is that beta minus decay results in a small increase in atomic number (from 10 to 11) and a decrease in atomic mass (from 92 to 89). beta decay is responsible for the loss of an element's nuclear stability, and it is one of the processes that facilitates the transformation of an unstable isotope into a more stable one. Gamma decay is another type of radioactive decay that results in the same changes to the atomic number and atomic mass as beta decay, but with the addition of a positron (an antimatter particle with the same mass as an electron, but with the opposite charge). Technetium (Tc) is an element that is well suited for medical nuclear imaging because it produces pure gamma radiation. Alpha decay is a type of radioactive decay in which an electron is released from an atom. This process reduces the atomic number of an element by two and reduces its atomic mass by four. Alpha decay is responsible for the loss of an element's nuclear stability, and it is one of the processes
• 00:30:00 In atomic theory, the nucleus is made up of smaller particles called subatomic particles. The nucleus is made of protons and neutrons, each of which has a positive and negative charge. The addition of a down quark to a nucleus provides extra mass.
• 00:35:00 The neutron and at least partially account for the mass differential between the proton and neutron. Interestingly, the quarks only make up about 2% of the total measured mass of the protons and neutrons. The remaining 98% appear to arise from the pure energy massless gluons holding the quarks together. The gluons therefore may be the link between energy and matter. In summary, nuclei with excess protons and neutrons undergo alpha decay reducing their atomic number by 2 and atomic mass by 4, nuclei with excess neutrons alone undergo beta minus decay converting a neutron to a proton and increasing their atomic number by 1, while leaving the atomic mass unchanged, and nuclei with insufficient energy differential between the parent and daughter nuclei undergo beta positive decay converting a proton to a neutron decreasing the atomic number by 1 and leaving the atomic mass unchanged. Isotopes with insufficient energy differential between the parent and daughter nuclei can undergo electron capture with the same result. Finally, nuclei with excess energy alone undergo gamma decay producing gamma rays while leaving the atomic number and atomic mass unchanged.