Nuclear Chemistry Test 4

Total Questions:50 Total Time: 75 Min

Remaining:

 

Questions 1 of 50

Question:Heavy water freezes at

Answers Choices:

\({0^0}C\)

\({3.8^0}C\)

\({38^0}C\)

\( - {0.38^0}C\)

Questions 2 of 50

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

Answers Choices:

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

Answers Choices:

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

Answers Choices:

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

Answers Choices:

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

Answers Choices:

Industry

Nuclear reactor

Medicine

Insecticide

Questions 7 of 50

Question:India conducted an underground nuclear test at

Answers Choices:

Tarapur

Narora

Pokhran

Pushkar

Questions 8 of 50

Question:Unit for radioactive constant is

Answers Choices:

\(Tim{e^{{\rm{-1}}}}\)

Time

\(Mole-tim{e^{-1}}\)

\(Time-mol{e^{-1}}\)

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

Answers Choices:

\(_{92}{U^{235}}\)

\(_6{C^{14}}\)

\(_6{C^{12}}\)

\(_{20}C{a^{40}}\)

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

Answers Choices:

\(_{28}^{60}Ni\)

\(_{27}^{60}Co\)

\(_{28}^{59}Ni\)

\(_{27}^{59}Co\)

Questions 11 of 50

Question:Fusion bomb involves

Answers Choices:

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

Answers Choices:

\(8,\,{C^{14}}\)

\(6,\,{C^{12}}\)

\(4,\,{C^{13}}\)

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

Answers Choices:

138

140

144

150

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

Answers Choices:

Gr.14

Gr.16

Gr.4

Gr.6

Questions 15 of 50

Question:Which one of the following is not correct

Answers Choices:

\(_3L{i^7}+{\,_1}{H^1}\to{\,_4}B{e^7}+{\,_0}{n^1}\)

\(_{21}S{c^{45}}+{\,_0}{n^1}\to{\,_{20}}C{a^{45}}+{\,_0}{n^1}\)

\(_{33}A{s^{75}}+{\,_2}H{e^4}\to{\,_{35}}B{r^{78}}+{\,_0}{n^1}\)

\(_{83}B{i^{209}}+{\,_1}{H^2}\to{\,_{84}}P{o^{210}}+{\,_0}{n^1}\)

Questions 16 of 50

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

Answers Choices:

36

39

41

44

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

Answers Choices:

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

Answers Choices:

\(6.93\times{10^2}{s^{-1}}\)

\(6.93\times{10^{-4}}s\)

\(6.93\times{10^{-4}}{s^{-1}}\)

\(6.93\times{10^3}s\)

Questions 19 of 50

Question:Radioactivity of naptunium stops when it is converted to

Answers Choices:

Bi

Rn

Th

Pb

Questions 20 of 50

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

Answers Choices:

Isothermals

Isotopes

Isentropus

Elementary particles

Questions 21 of 50

Question:Tritium is an isotope of

Answers Choices:

Hydrogen

Titanium

Tantalum

Tellurium

Questions 22 of 50

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

Answers Choices:

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

Answers Choices:

\(_{30}Z{n^{71}}\)

\(_{30}Z{n^{66}}\)

\(_{30}Z{n^{64}}\)

None of these

Questions 24 of 50

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

Answers Choices:

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

Answers Choices:

2

3

1

4

Questions 26 of 50

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

Answers Choices:

1/3

3/1

1/1

1/4

Questions 27 of 50

Question:An ordinary oxygen contains

Answers Choices:

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

Answers Choices:

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

Answers Choices:

\({C^{12}}\) 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

Answers Choices:

Proton

Positron

Electron

Neutron

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

Answers Choices:

4

9

7

6

Questions 32 of 50

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

Answers Choices:

Positron

Proton

Neutrino

Meson

Questions 33 of 50

Question:The positron is

Answers Choices:

\(_{-1}{e^0}\)

\(_{+1}{e^0}\)

\(_1{H^1}\)

\(_0{n^1}\)

Questions 34 of 50

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

Answers Choices:

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

Answers Choices:

Hg

Pb

Ra

U

Questions 36 of 50

Question:Alpha rays consist of a stream of

Answers Choices:

\({H^+}\)

\(H{e^{+2}}\)

Only electrons

Only neutrons

Questions 37 of 50

Question:Which is the correct statement

Answers Choices:

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

Answers Choices:

Positive charge

Negative charge

No charge

Sometimes positive charge, sometimes negative charge

Questions 39 of 50

Question:Which is not emitted by radioactive substance

Answers Choices:

\(\alpha\)-rays

\(\beta\)-rays

Positron

Proton

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

Answers Choices:

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

Answers Choices:

1

1/16

1/4

1/8

Questions 42 of 50

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

Answers Choices:

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

Answers Choices:

\(\frac{1}{\lambda},\,\frac{{\ln\,2}}{\lambda}\)

\(\frac{{\ln\,2}}{\lambda},\,\frac{1}{\lambda}\)

\(\lambda\,\ln\,2,\,\frac{1}{\lambda}\)

\(\frac{\lambda}{{\ln\,2}},\,\frac{1}{\lambda}\)

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

Infinite

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

Answers Choices:

\(4.8\times{10^{10}}\)

\(9.2\times{10^6}\)

\(3.7\times{10^{10}}\)

Zero

Questions 48 of 50

Question:The activity of radio isotope changes with

Answers Choices:

Temperature

Pressure

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

Answers Choices:

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