Chapter 25-Applications of Radioactivity

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How are radioactive tracers used by the doctors to help them identify the diseased organs?
Radioactive isotopes are used as tracers and they are chemical compounds that emit gamma radiation. The tracer is taken orally by the patient or injected. Gamma ray camera is then used to trace its passage around the body.
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Name a radioactive isotope used as tracer and identify its role in the body.
The isotope iodine-123 is absorbed by the thyroid gland and this isotope decays and emits gamma radiation. Gamma ray camera is used to form clear image of thyroid gland.
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What is irradiation?
Ionizing radiation is used to kill micro-organisms on surgical instruments and other medical equipment. This technique is called irradiation.
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State some uses of gamma rays.
Gamma rays are used to check for imperfections in welded joints and for flaws in metal castings. Gamma radiation is used in gauging. Gamma radiation is used to sterilize medical equipment and food. It's also used to track the level of sewage.
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What are the advantages of radioactive gauging?
Firstly, there is no contact with the material being gauged. Also coal dust might cause false readings with an optical gauging system, so a radioactive gauging system is more accurate.
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What is radiocarbon dating and how can it be used to estimate the age of a dead sample of plant or animal?
Radiocarbon dating measures the level of an isotope called carbon-14. The amount of carbon-14 present in the sample of a dead organism is found by measuring the activity of the sample. This is compared with the carbon-14 of a living organism.
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How do beta and gamma radiation provide a health hazard when outside the body?
Both can penetrate skin and flesh and cause cell damage by ionization.
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How should radioactive materials be handled?
The samples can be stored in lead containers, they should be labelled as radiation hazards, they should be handled using tongs and people handling them should wear lead lined suits.
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What is thermoluminescence?
It means that the exposed material will give out light when it is warmed.
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Why do alpha particles have a health hazard when they are inside the body?
Alpha particles have the greatest ionizing effect and prolonged exposure to alpha radiation inside the body can cause cells to be killed, damaged and even mutation of cells can result.
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To reduce the damage to healthy tissues, which two radiations are used to target the location of cancer in the body?
Beta radiation and alpha radiation is used, since both of these radiations have a short range in the body. Thus, they will only affect a small volume of tissue close to the target.
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Other cards in this set

Card 2

Front

Name a radioactive isotope used as tracer and identify its role in the body.

Back

The isotope iodine-123 is absorbed by the thyroid gland and this isotope decays and emits gamma radiation. Gamma ray camera is used to form clear image of thyroid gland.

Card 3

Front

What is irradiation?

Back

Preview of the front of card 3

Card 4

Front

State some uses of gamma rays.

Back

Preview of the front of card 4

Card 5

Front

What are the advantages of radioactive gauging?

Back

Preview of the front of card 5
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