28.4Radiation in Your Life

Ionizing Radiation Radiation with enough energy to knock

electrons off atoms and produce ions X-rays and radiation emitted by radioisotopes

are ionizing radiation Not detectable by senses Geiger counter detects this type of radiation

Geiger counter Used to detect beta radiation Radiation enters gas filled tube and creates

ions which conduct electricity Bursts of current creates audible clicks or

starts electronic counter

Scintillation counter Device with a surface coated with phosphor Ionizing radiation causes the phosphor to

“flash” when it hits it Number of flashes is detected electronically TV screens use ZnS as the phosphor and

electrons are shot at the screen . The scintillations produce a pattern which is the picture we see

Film Badges Several layers of photographic film covered

with black, lightproof paper Badges are worn by people who work near

radiation sources and are developed at specific intervals

Used to detect how much radiation a person is exposed to

Radiation Uses Used to detect trace amount of elements by

neutron activation Neutron activation can be used in forensics-

to detect art forgeries, and analyze gunpowder Radioactive isotopes can be used to trace

where elements go- as in chemical reactions Radioactive tracers can trace where

substances travel

Radiation Uses Radioisotopes can help diagnose disease- I-131 helps diagnose thyroid problems;

technetium-99 diagnoses brain tumors and liver problems; P-32 used for skin cancer

Radiation is used to treat cancer; Co-60 and Cs-137 ; often gamma sources are used- c ancers are more susceptible to high energy radiation

Radiation Uses Salts of radiactive isotopes can be sealed in

gold tubes and directly implanted in tumors- emit beta or gamma