Nuclear Chemistry Test 4

Total Questions:50 Total Time: 75 Min



Questions 1 of 50

Question:Heavy water freezes at

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\( - {0.38^0}C\)

Questions 2 of 50

Question:To determine the masses of the isotopes of an element which of the following techniques is useful

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The acceleration of charged atoms by an electric field and their subsequent deflection by a variable magnetic field

The spectroscopic examination of the light emitted by vaporised

elements subjected to electric discharge

The photographing of the diffraction patterns which arise when X-rays are passed through crystals

The bombardment of metal foil with alpha particles

Questions 3 of 50

Question:The radioisotope, tritium \((_1^3H)\) has a half-life of 12.3 years. If the initial amount of tritium is 32 mg. How many milligrams of it would remain after 49.2 years

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8 mg

1 mg

2 mg

4 mg

Questions 4 of 50

Question:When a radioactive substance is subjected to vacuum, the rate of disintegration per second

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Increases considerably

Increases only if the products are gaseous

Is not affected

Suffers a slight decrease

Questions 5 of 50

Question:A radio isotope will not emit

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Gamma and alpha rays simultaneously

Gamma rays only

Alpha and beta rays simultaneously

Beta and gamma rays simultaneously

Questions 6 of 50

Question:\({D_2}O\) is used in

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Nuclear reactor



Questions 7 of 50

Question:India conducted an underground nuclear test at

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Questions 8 of 50

Question:Unit for radioactive constant is

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Questions 9 of 50

Question:Which of the following is used in dating archeological findings or In a method of absolute dating of fossils a radioactive element is used. It is

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Questions 10 of 50

Question:The radioactivity isotope \(_{27}^{60}Co\) which is used in the treatment of cancer can be made by (n, p) reaction. For this reaction the target nucleus is

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Questions 11 of 50

Question:Fusion bomb involves

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Combination of lighter nuclei into bigger nucleus

Destruction of heavy nucleus into smaller nuclei

Combustion of oxygen

Explosion of TNT

Questions 12 of 50

Question:The number of neutrons in the parent nucleus which gives \({N^{14}}\) on \(\beta\)-emission and the parent nucleus is

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None of these

Questions 13 of 50

Question:After the emission of \(\alpha\)-particle from the atom \(_{92}{X^{238}}\), the number of neutrons in the atom will be

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Questions 14 of 50

Question:A nuclide of an alkaline earth metal undergoes radioactive decay by emission of the \(\alpha-\)particles in succession. The group of the periodic table to which the resulting daughter element would belong is

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Questions 15 of 50

Question:Which one of the following is not correct

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Questions 16 of 50

Question:Atomic number after a \(\beta\)-emission from a nucleus having atomic number 40, will be

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Questions 17 of 50

Question:A certain nuclide has a half-life period of 30 minutes. If a sample containing 600 atoms is allowed to decay for 90 minutes, how many atoms will remain

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200 atoms

450 atoms

75 atoms

500 atoms

Questions 18 of 50

Question:If half-life of a certain radioactive nucleus is \(1000\,s,\) the disintegration constant is

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Questions 19 of 50

Question:Radioactivity of naptunium stops when it is converted to

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Questions 20 of 50

Question:Substances which have identical chemical properties but differ in atomic weights are called

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Elementary particles

Questions 21 of 50

Question:Tritium is an isotope of

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Questions 22 of 50

Question:An isotope of ‘parent’ is produced, when its nucleus loses

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One \(\alpha\)-particle

One \(\beta\)-particle

One \(\alpha\) and two \(\beta\)-particles

One \(\beta\) and two \(\alpha\)- particles

Questions 23 of 50

Question:Which of the following isotopes is likely to be most stable

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None of these

Questions 24 of 50

Question:Addition of two neutrons in an atom \(A\) would

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Change the chemical nature of \(A\)

Produce an isobar of \(A\)

Produce an isotope of A

Produce another element

Questions 25 of 50

Question:Atomic weight of the isotope of hydrogen which contains 2 neutrons is the nucleus would be

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Questions 26 of 50

Question:In chlorine gas, ratio of \(C{l^{35}}\) and \(C{l^{37}}\)is

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Questions 27 of 50

Question:An ordinary oxygen contains

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Only \(O-16\) isotopes

Only \(O-17\) isotopes

A mixture of \(O-16\) and \(O-18\) isotopes

A mixture of O – 16, \(O-17\) and \(O-18\) isotopes

Questions 28 of 50

Question:Which can be used for carrying out nuclear reaction

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Uranium – 238

Neptunium – 239

Thorium – 232

Plutonium – 239

Questions 29 of 50

Question:On comparing chemical reactivity of \({C^{12}}\) and \({C^{14}}\), it is revealed that

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\({C^{12}}\) is more reactive

\({C^{14}}\) is more reactive

Both are inactive

Both are equally active

Questions 30 of 50

Question:In the reaction \(_{93}N{p^{239}}{\to_{94}}P{u^{239}}\) + (?), the missing particle is

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Questions 31 of 50

Question:According to the nuclear reaction \(_4Be{+_2}H{e^4}{\to_6}{C^{12}}{+_0}n{^1}\), mass number of \((Be)\) atom is

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Questions 32 of 50

Question:A particle having the same charge and 200 times greater mass than that of electron is

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Questions 33 of 50

Question:The positron is

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Questions 34 of 50

Question:Nuclear reactivity of Na and \(N{a^+}\) is same because both have

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Same electron and proton

Same proton and same neutron

Different electron and proton

Different proton and neutron

Questions 35 of 50

Question:Which of the following is the heaviest metal

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Questions 36 of 50

Question:Alpha rays consist of a stream of

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Only electrons

Only neutrons

Questions 37 of 50

Question:Which is the correct statement

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Isotopes are always radioactive

\(\beta\)-rays are always negatively charged particles

\(\alpha\)-rays are always negatively charged particles

\(\gamma\)-rays can be deflected in magnetic field

Questions 38 of 50

Question:There exists on \(\gamma\)-rays

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Positive charge

Negative charge

No charge

Sometimes positive charge, sometimes negative charge

Questions 39 of 50

Question:Which is not emitted by radioactive substance

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Questions 40 of 50

Question:The atomic mass of an element is 12.00710 amu. If there are 6 neutrons in the nucleus of the atom of the element, the binding energy per nucleon of the nucleus will be

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7.64 MeV

76.4 MeV

764 MeV

0.764 MeV

Questions 41 of 50

Question:Half-life period of a metal is 20 days. What fraction of metal does remain after 80 days

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Questions 42 of 50

Question:During a negative \(\beta\)-decay

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An atomic electron is ejected

An electron which is already present within the nucleus is ejected

A neutron in the nucleus decays emitting an electron

A part of the binding energy of the nucleus is converted into an electron

Questions 43 of 50

Question:The decay constant of a radioactive sample is \('\lambda'\). The half-life and mean life of the sample are respectively

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Questions 44 of 50

Question:Half-life of \(10gm\) of radioactive substance is 10 days. The half-life of \(20gm\) is

Answers Choices:

10 days

20 days

25 days


Questions 45 of 50

Question:\(8gm\) of the radioactive isotope, cesium-137 were collected on February 1 and kept in a sealed tube. On July 1, it was found that only \(0.25gm\) of it remained. So the half-life period of the isotope is

Answers Choices:

37.5 days

30 days

25 days

50 days

Questions 46 of 50

Question:The half-life of \(_{92}{U^{238}}\) is \(4.5\times{10^9}\) years. After how many years, the amount of \(_{92}{U^{238}}\) will be reduced to half of its present amount

Answers Choices:

\(9.0\times{10^9}\) years

\(13.5\times{10^9}\) years

\(4.5\times{10^9}\) years

\(4.5\times{10^{4.5}}\) years

Questions 47 of 50

Question:Radium has atomic weight 226 and a half-life of 1600 years. The number of disintegrations produced per second from \(1gm\) are

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Questions 48 of 50

Question:The activity of radio isotope changes with

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Chemical environment

None of these

Questions 49 of 50

Question:A certain nuclide has a half-life of 25 minutes. If one starts with 100 g of it, how much of it will remain at the end of 100 minutes

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1.0 g

4.0 g

6.25 g

12.50 g

Questions 50 of 50

Question:If 8.0 g of a radioactive substance has a half-life of 10 hrs., the half life of 2.0 g of the same substance is

Answers Choices:

2.6 hr

5 hr

10 hr

40 hr