Post on 04-Jan-2016
Ch. 25.5Applications and Effects of
Nuclear Reactions
CHM Hon.
Last class…we talked about nuclear fission:
Today…
• We will discuss another application of nuclear chemistry: MEDICINE
Detecting Radioactivity
• Ionizing radiation = radiation energetic enough to ionize matter with which it collides– Geiger Counter makes use of ionizing
radiation
Detecting Radioactivity–Geiger counter: radiation detection device
Detecting Radioactivity
• Scintillation counter – Uses phosphor-coated surface to detect
radiation– Scintillations = bright flashes of light produced
when ionizing radiation excites the electrons in certain types of atoms (phosphors)
• The number and brightness is detected / recorded, determines the amount of ionizing radiation present
Uses of radiation
• Neutron activation analysis– Detects trace amounts of elements in a
sample– Used in computer chip technology (analysis of
composition)– Bombardment with stream of neutrons– Type of radiation emitted determines the
types / quantities of elements present
Uses of Radiation
• Used to follow the course of an element through a chemical reaction– Helps Scientists understand processes– Radiotracer = radioisotope that emits non-
ionizing radiation and is used to signal the presence of an element or specific substance.
• Iodine-131
Uses of Radiation
• Positron emission transaxial tomograpgy (PET)
Uses of Radiation
• Radiation therapy– Used to treat cancer by destroying unhealthy
cells, fast-growing cells– Down side: also kills good cells!
Biological Effects of Radiation
• Can be very harmful
• Damaged produced depends on: – energy of radiation– type of tissue– Distance
• Gamma rays easily penetrate human skin
Biological Effects of Radiation
• Ionizing radiation damage to living systems– SOMATIC: affects non-reproductive body
tissue– GENETIC: damages reproductive tissue
Biological Effects of Radiation
• Dose – the amount of radiation your body absorbs from a radioactive source– Rad (Radiation absorbed dose)– Rem (roentgen equivalent for man)