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II. There are several definitions in the text. What are they? Complete the
sentences.
1. Sometimes the nucleus of an atom is not stable. The change is called a
.
2. Emitting particles or waves from the nucleus is called
.
3. The
of a radioactive isotope
is the time after which, on
average, half of the original material will have decayed.
4.
is a random process which gives out heat.
5. The particles or waves that are emitted are called
.
III. Are these sentences true or false?
1. There are not natural radioactive materials in the ground at all.
2. Uranium and plutonium are strongly radioactive but have very short
half-lives.
3. The radiation was classified by E. Rutherford as alpha, beta, and
gamma rays (for the first three letters of the Greek alphabet)
according to their ability to penetrate matter and ionize air.
4. Radiation causes health problems by killing cells in the body, and the
amount and type of damage done depends
on the dose of radiation
received and the time over which the dose is spread out.
5. Gamma radiation is the least penetrating of the three and will not
travel through several centimeters of lead.
B. Work with language
I. Give Russian equivalents to the following phrases:
a) nuclear chain reaction
b)
single fission process
c) vertical cloud chamber
d)
cosmic ray particle
e) wide energy spread
f) total energy liberation
g)
thick material layer
h) critical size level
i)
nuclear power production
j) ordinary steam turbine
k) original fission neutrons
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II. Put the words into the right order. Check your answers with the text.
1. rays/ gamma/ comes from/ as/ Some/ cosmic/ radiation/ space.
2. with/ a nucleus/ beta/ an excited/ energy/ After/ or/ excess/ alpha/
undergoes/ left in/ it is/ decay/ state/ often.
3. was/ in / A. H. Becquerel/ Radioactivity/ by/ 1896/ discovered.
4. emit/ a/ nucleus/ will/ or/ waves/ When/ it/ particles/ some/ decays.
5. gives out/ decay/ a/ process/ heat/ Radioactivity/ random/ which/ is.
III. Guess the words:
1) seod
2) barobs
3) tafal
4) cyade
5) lentmee
IV. Skim the passage as fast as possible and find answers to the following
questions.
1) What is the main problem in maintaining a steady chain reaction?
2) What are "control rods" used for?
3) What is the design of a "swimming pool" reactor?
4) What purposes are nuclear power reactors used for?
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