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प्रश्न
(a) What are radioactive isotopes ? Give two examples of radioactive isotopes.
(b) Give any two uses of radioactive isotopes.
(c) An element Z contains two naturally occurring isotopes `""_17^35"Z"` and `""_17^37"Z"`. If the average atomic mass of this element be 35.5 u, calculate the percentage of two isotopes.
उत्तर
(a) Those isotopes which are unstable due to the presence of extra neutrons in their nuclei and emit various types of radiations are called radioactive isotopes. The radiations emitted are in the form of alpha particles, beta particles and gamma rays.
Common examples of radioactive isotopes are Arsenic−74, Iodine−131 and Cobalt−60.
(b) Uses of isotopes−
(i) Cobalt−60 is used in the treatment of cancer cells. When the high−energy gamma radiations emitted by cobalt−60 isotopes are directed at the cancerous tumours , the cells are burnt.
(ii) Iodine−131 is used as a tracer to determine the rate at which the thyroid gland takes up iodine.
(c) Average atomic mass of Z = 35.5u
Let the % of isotope with mass number 35 be x
Then the % of isotope with mass number 37 will be 100 - x.
Average Atomic Mass Of Chlorine=`35xx[x/100] + 37xx["100-x"/100]`
35 = `"35x"/100" + "37(100-x)"/100"`
x = 75
It means that the % of the isotope `""_17^35"Cl"` is 75 and the % of the isotope `""_17^35"Cl"` is 25.
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संबंधित प्रश्न
State one use of radioactive isotopes in medicine.
Name the Radioactive Isotope Which is Used in the Treatment of Cancer.
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Which of the following pairs are isotopes ? Give reasons for your choice :
(i) `""_26^58"A"`, `""_28^58"B"` or (ii) `""_35^79"X"`, `""_35^80"Y"`
Name the atoms of a substance having same atomic number, but different mass numbers. Give one example of such a substance. How do the structures of such atoms differ?
Four elements A, B, C, D are given :
- A shows the presence of 20 neutrons, 17 protons and 17 electrons.
- B shows the presence of 18 neutrons, 17 protons and 17 electrons.
- C shows the presence of 10 neutrons, 9 protons and 10 electrons.
- D shows the presence of 4 neutrons, 3 protons and 2 electrons.
State which of the above is –
- an anion
- a cation
- a pair of isotopes.
Write the formula of the compound formed between D and C.
Among the following the odd pair is
______ isotope is used in the nuclear reactors.
Why do \[\ce{^35_17{CI}}\] and \[\ce{^37_17{CI}}\] and have the same chemical properties? In what respect do these atoms differ?
List the uses of isotopes.
