Nuclear Chemistry Test 6

Total Questions:50 Total Time: 75 Min



Questions 1 of 50

Question:In the nuclear reactors the speed of the neutrons is slowed down by

Answers Choices:

Heavy water

Ordinary water

Zinc rods

Molten caustic soda

Questions 2 of 50

Question:By which law, energy produced in nuclear reaction is given

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Graham’s law

Charle’s law

Gas Lussac’s Law

Einstein’s law

Questions 3 of 50

Question:A radioactive isotope has a half-life of 10 years. What percentage of the original amount of it remain after 20 years

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Questions 4 of 50

Question:In a chain reaction, uranium atom gets fissioned forming two different materials. The total weight of these put together is

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More than the weight of parent uranium atom

Less than the weight of parent uranium atom

More or less depends upon experimental conditions

Neither more nor less

Questions 5 of 50

Question:A piece of wood was found to have \({C^{14}}/{C^{12}}\) ratio 0.7 times that in a living plant. The time period when the plant died is (Half-life of \({C^{14}}=5760\,yrs)\)

Answers Choices:

2770 yrs

2966 yrs

2980 yrs

3070 yrs

Questions 6 of 50

Question:When a slow neutron goes sufficiently close to a \({U^{235}}\) nucleus, then the process which takes place is

Answers Choices:

Fusion of \({U^{235}}\)

Fission of \({U^{235}}\)

Fusion of neutron

First (1) then (2)

Questions 7 of 50

Question:The huge amount of energy which is released during atomic fission is due to

Answers Choices:

Loss of mass

Loss of electrons

Loss of protons

Loss of \(\alpha\)-particles

Questions 8 of 50

Question:The measure of binding energy of a nucleus is the

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Mass defect

Energy of protons

Energy of neutrons

Total energy of nucleons

Questions 9 of 50

Question:The first controlled artificial disintegration of an atomic nucleus was achieved by

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Questions 10 of 50

Question:Which of the following is an example of nuclear fission

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Questions 11 of 50

Question:The \({C^{14}}\)to \({C^{12}}\) ratio in a wooden article is 13% that of the fresh wood. Calculate the age of the wooden article. Given that the half-life of \({C^{14}}\) is 5770 years

Answers Choices:

16989 years

16858 years

15675 years

17700 years

Questions 12 of 50

Question:Hydrogen bomb is based on the principle of

Answers Choices:

Nuclear fission

Natural radioactivity

Nuclear fusion

Artificial radioactivity

Questions 13 of 50

Question:\(\beta\)-particles are emitted from the atom

Answers Choices:

Due to disintegration of neutron

Due to disintegration of proton

Due to removal of electron from \(K\) shell

Due to removal of electron from outermost orbit

Questions 14 of 50

Question:\(Nd\,(Z=60)\) is a member of group -3 in periodic table. An isotope of it is \(\beta\)-active. The daughter nuclei will be a member of

Answers Choices:

Group -3

Group – 4

Group -1

Group - 2

Questions 15 of 50

Question:On bombarding \(_8{O^{16}}\) with deutrons, the nuclei of the product formed will be

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Questions 16 of 50

Question:An element with atomic number 84 and mass number 218 loses one \(\alpha\)-particle and two \(\beta\)-particles in three successive stages, the resulting element will have

Answers Choices:

At. no. 84 and mass number 214

At. no. 82 and mass number 214

At. no. 84 and mass number 218

At. no. 82 and mass number 218

Questions 17 of 50

Question:\(\alpha\)-rays have high ionization power because they possess

Answers Choices:

Lesser kinetic energy

Higher kinetic energy

Lesser penetrating power

Higher penetrating power

Questions 18 of 50

Question:When radium atom which is placed in II group, loses an \(\alpha\)- particle, a new element is formed which should be placed in group

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Questions 19 of 50

Question:All the nuclei from the initial element to the final element constitute a series which is called

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b-g series

Disintegration series

Questions 20 of 50

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

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Questions 21 of 50

Question:Isotopes are atoms having the same

Answers Choices:

Atomic mass

Mass number

Atomic number

Number of neutrons

Questions 22 of 50

Question:Successive emission of an \(\alpha\)-particle and two \(\beta\)-particles by an atom of an element results in the formation of its

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Questions 23 of 50

Question:Isobaric atoms may contain

Answers Choices:

Same number of \({p^+}\) and different number of \({n^0}\)

Same number of \({n^0}\) and different number of \({p^+}\)

Same number of both \({p^+}\) and \({n^0}\)

Different numbers of both \({p^+}\) and \({n^0}\)

Questions 24 of 50

Question:\(_{20}{X^{40}}\) and \(_{21}{X^{40}}\) are

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Questions 25 of 50

Question:The symbol of an isotope is \(_{32}{X^{65}}\), this reveals that

Answers Choices:

Its atomic number is 32 and atomic weight is 65

Its atomic number is 65

It has 65 electrons

It has 32 neutrons

Questions 26 of 50

Question:Two atoms have the same atomic mass but different atomic numbers. Such atoms are called as

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Questions 27 of 50

Question:Which of the following are pairs of isotopes

Answers Choices:

\(_1^2{H^+}\) and \(_1^3H\)

\(_1^3H\) and \(_2^4{H^-}\)

\(_2^3He\) and \(_2^4He\)

\(_6^{12}C\) and \(_7^{14}{N^+}\)

Questions 28 of 50

Question:Which among the following isotope is not found in natural uranium

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Questions 29 of 50

Question:A nuclear reaction must be balanced in terms of

Answers Choices:

Only energy

Only mass

Mass and energy

None of these

Questions 30 of 50

Question:In the following nuclear reaction, the other product is \(_{52}T{e^{130}}{+_1}{H^2}{\to_{53}}{I^{131}}+?\)

Answers Choices:


Alpha particle

One neutron


Questions 31 of 50

Question:The atomic mass of lead is 208 and atomic number is 82. The atomic mass of bismuth is 209 and atomic number is 83. The ratio of n/p in the atom is

Answers Choices:

Higher of lead

Higher of bismuth


None of these

Questions 32 of 50

Question:Which of the following is an \(n,\,p\) reaction

Answers Choices:


\({_7}{N^{14}} + {\,_1}{H^1} \to {\,_8}{O^{15}}\)



Questions 33 of 50

Question:The nucleus of an atom is made up of X protons and Y neutrons. For the most stable and abundant nuclei

Answers Choices:

X and Y are both even

X and Y are both odd

X is even and Y is odd

X is odd and Y is even

Questions 34 of 50

Question:Atom A possesses higher values of packing fraction than atom B. The relative stabilities of A and B are

Answers Choices:

A is more stable than B

B is more stable than A

A and B both are equally stable

Stability does not depend on packing fraction

Questions 35 of 50

Question:For the nuclear reaction, \(_{12}^{24}Mg+{\,_1}{D^2}\to\alpha+?\), the missing nucleide is

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Questions 36 of 50

Question:\(_Z{X^M}{+_2}H{e^4}{\to_{15}}{P^{30}}{+_0}{n^1}\). Then

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Questions 37 of 50

Question:Radioactivity was discovered by

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Henry Becquerel


J. J. Thomson

Madam Curie

Questions 38 of 50

Question:Which of the following is radioactive element

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Questions 39 of 50

Question:During \(\beta \) -decay

Answers Choices:

An atomic electron is ejected

An electron which is already present with in the nucleus is ejected

A neutron in the nucleus decays emitting an electron

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

Questions 40 of 50

Question:The element californium belongs to the family of

Answers Choices:

Actinide series

Alkali metal family

Alkaline earth family

Lantanide series

Questions 41 of 50

Question:\(1.0g\) of a radioactive isotope was found to reduce to \(125\,mg\) after 24 hours. The half-life of the isotope is

Answers Choices:

8 hours

24 hours

6 hours

4 hours

Questions 42 of 50

Question:A radioactive element decays at such a rate that after 15 minutes only 1/10 of the original amount is left. How many more minutes will be needed when only 1/100 of the original amount will be left

Answers Choices:

1.5 minutes

15.0 mintues

16.5 minutes

30 minutes

Questions 43 of 50

Question:If 12 g of sample is taken, and 6 g of a sample decays in 1 hr. The amount of sample showing decay in next hour is

Answers Choices:

3 g

1 g

2 g

6 g

Questions 44 of 50

Question:What will be half-life period of a nucleus if at the end of 4.2 days, \(N=0.798\,{N_0}\)

Answers Choices:

15 days

10 days

12.83 days

20 days

Questions 45 of 50

Question:The half-life of \(C{o^{60}}\) is 7 years. If one \(gm\) of it decays, the amount of the substance remaining after 28 years is

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Questions 46 of 50

Question:A radioactive isotope decays at such a rate that after 96 minutes only \(\frac{1}{8}th\) of the original amount remains. The half-life of this nuclide in minutes is

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Questions 47 of 50

Question:A radioactive element has half-life of one day. After three days, the amount of the element left will be

Answers Choices:

1/2 of the original amount

1/4 of the original amount

1/8 of the original amount

1/16 of the original amount

Questions 48 of 50

Question:The radioactivity due to \({C^{14}}\) isotope (half-life 6000 years) of a sample of wood from an ancient tomb was found to be nearly half that of fresh wood, the tomb is therefore about

Answers Choices:

3000 years old

6000 years old

9000 years old

1200 years old

Questions 49 of 50

Question:If the disintegration constant is \(6.93\times{10^{-6}},\) then half-life of \(_6{C^{14}}\) will be

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Questions 50 of 50

Question:The decay constant of \(R{a^{226}}\) is \(1.37\times{10^{-11}}{\sec^{-1}}\). A sample of \(R{a^{226}}\) having an activity of 1.5 millicurie will contain ...... atoms

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