Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions. Discoveries in nuclear physics have led to applications in many fields. This includes nuclear power, nuclear weapons, nuclear medicine and magnetic resonance imaging, industrial and agricultural isotopes, ion implantation in materials engineering, and radiocarbon dating in geology and archeology. Such applications are studied in the field of nuclear engineering. 5.1: The Discovery of Radiation Henri Becquerel, Marie Curie, and Pierre Curie shared the discovery of radioactivity. 5.2: The Electromagnetic Spectrum What we know as light is more properly called electromagnetic radiation. We know from experiments that light acts as a wave. As such, it can be described as having a frequency and a wavelength. The wavelength of light is the distance between corresponding points in two adjacent light cycles, and the frequency of light is the number of cycles of light that pass a given point in one second. 5.3: Types of Radiation In natural radioactive decay, three common emissions occur. When these emissions were originally observed, scientists were unable to identify them as some already known particles and so named them alpha particles (α), beta particles, (β), and gamma rays (γ). 5.4: Ionizing Radiation and Non-ionizing Radiation All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. 5.5: The Basics of Skin Cancer Of all the types of ionizing radiation, people come into more contact with ultraviolet radiation, which is produced naturally by the sun and artificially by lamps and tanning bed. Scientific research has correlated certain types of skin cancers (mainly basal and squamous cell) with the use of these devices. Besides skin cancer, tanning beds cause premature aging and damage to your eyes. If a tanning bed is not properly sanitized between uses, skin diseases can be transmitted from one consumer to 5.6: Measuring Radiation Various devices, including Geiger counters, scintillators, and dosimeters, are used to detect and measure radiation, and monitor radiation exposure. We use several units to measure radiation: becquerels or curies for rates of radioactive decay; gray or rads for energy absorbed; and rems or sieverts for biological effects of radiation. Exposure to radiation can cause a wide range of health effects, from minor to severe, and including death. 5.7: Calculating Half-Life During natural radioactive decay, not all atoms of an element are instantaneously changed to atoms of another element. The decay process takes time and there is value in being able to express the rate at which a process occurs. A useful concept is half-life, which is the time required for half of the starting material to change or decay. 5.8: Using Nuclear Science to Diagnose Disease The field of nuclear medicine has expanded greatly in the last twenty years. A great deal of the expansion has come in the area of imaging. This section will focus on nuclear medicine involving the types of nuclear radiation introduced in this chapter. 5.9: Therapeutic Radiation Radiation Therapy is used as a treatment to control malignant cells within cancer patients. Oncologists used radiation therapy frequently to help slow or cure the spread of cancer within inidivduals. Radiation is specifically applied to malignant tumors in order to shrink them in size, while hopefully not causing more damage to surrounding healthy cells. 5.10: Non-medical Applications of Nuclear Science Radioactive isotopes have a variety of applications. Generally, however, they are useful because either we can detect their radioactivity or we can use the energy they release. 5.E: Basics of Nuclear Science (Exercises) These are homework exercises to accompany Chapter 5 of the Furman University's LibreText for CHE 101 - Chemistry and Global Awareness.