WEEK: FIVE
SUBJECT: BASIC SCIENCE
CLASS: GRADE 9
TERM: SECOND
TOPIC: RADIOACTIVITY (CONTINUED)
USES OF RADIOACTIVITY
1.
Nuclear
radiation is used in nuclear power plants.
2.
Radioactivity is used in the preservation of food grains and seeds.
3.
Cancer Treatment: Some of the isotopes are used in the treatment of cancer
4. Some
of the isotopes are used to study the proper functioning of internal organs.
diagnosing and treating various diseases.
5.
Sterilizing: Gamma radiations are used to sterilize surgical instruments.
6. Radio
phosphorus is used for studying the rate of phosphorus assimilation by the
plant.
7.
Nuclear radiation is used for finding out the faults in metal structures,
cracks in concrete structures.
8. It is
used for monitoring the flow of rivers.
9. It is
used for measuring the thickness of paper and kitchen foil.
10. It
is used for finding the age of ancient remains.
11. It
is used for preparing synthetic elements.
12. It
is used in smoke detectors.
DANGERS OF RADIOACTIVE RAYS
If
something is radioactive then, it sends out radiation that you can't turn off
or affect in any way by any normal means. If something is radioactive then the
type of radiation it gives off is called nuclear radiation because it comes
from changes in the nucleus of atoms. You can't get rid of energy but it does
tend to get spread thinner and thinner and become impossible to detect. This is
what happens to all radiation in the end. The energy gets spread so thin that
you can't tell it's there anymore. Radiation can cause damage to our cells causing
burns, sickness, diarrhoea and vomiting, infertility and sometimes death. Small
doses can damage our DNA which can lead to cancer when we're older.
Alpha Decay occurs
when the neutron to proton ratio is too low. Alpha particles are highly
ionizing (e.g., deposits energy over a short distance). Since alpha particles
lose energy over a short distance, they cannot travel far in most media.
Consequently, alpha particles will not normally penetrate the outermost layer
of the skin. Therefore, alpha particles pose little external radiation field
hazard. Shielding of alpha particles is easily accomplished with minimal
amounts of shielding.
Beta Decay occurs
when the neutron to proton ratio is too high. Beta particles are less ionizing
than alpha particles. The range of beta particles depends on the energy, and
some have enough to be of concern regarding external exposure. Energetic beta
particles can penetrate into the body and deposit to internal structures near
the surface. Since beta particles are less ionizing than alpha particles,
greater shielding is required.
Gamma Rays are not
particulate radiation like the alpha and beta, but a form of high-energy
electromagnetic wave. Gamma rays are the least ionizing of the three forms discussed. Since gamma radiation can travel far
in air, it poses a significant external radiation hazard. Further, if ingested,
it may pose an internal radiation hazard. Shielding of gamma rays is normally
accomplished with high atomic number materials such as lead.
The radiation is more dangerous to children
than adults because children are smaller than adults, so the ionizing radiation
is more concentrated in terms of body size. Because of the smaller body size, a
greater percentage of the body is damaged, including vital organs. Since a
child is still developing physically (intellectually, emotionally, etc), the
radiation can damage this process before it is completed having an adverse
effect over the rest of the child’s life.
ASSIGNMENT
OBJECTIVE:
1.
This scientist died of radioactive poison A. Becquerel B. Marie Curie C. Geiger
Muller D. Marsden
2.
Workers in radioactive laboratories are shielded from the harmful effects of
radiation by using A. thick lab coats B. thick blocks of lead C. cosmic rays in
the lab D. non-radioactive pills daily after work
3.
Radioactivity has wide application in the following field except A. medicine B.
industries C. agriculture D. weather forecast
4.
Radiation is detected by the following except A. diffusion cloud chamber B.
scintillation counter C. Geiger-Muller counter D. pulse current
5.
Alpha particle is A. helium nucleus B. electron C. proton D. neutron
6.
Beta particle is A. proton B. electron C. neutron D. helium nucleus
THEORY:
1.
State fives uses of radioactivity.
2.
Explain the dangers of radioactivity.
3.
Explain alpha, beta and gamma decay.
0 Comments