# Nuclear Chemistry Test 5

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:Neutron is used as a

Reducing agent

Moderator

Tracer

In biological programme

## Questions 2 of 50

Question:Hydrogen bomb is based on the phenomenon of

Nuclear fission

Nuclear fusion

Nuclear explosion

Disintegration

## Questions 3 of 50

Question:What is the packing fraction of $$_{26}^{56}Fe$$ (Isotopic mass = 55.92066)

$$-14.167$$

$$173.90$$

$$-14.187$$

$$-73.90$$

## Questions 4 of 50

Question:The energy released in an atom bomb explosion is mainly due to

Release of neutrons

Release of electrons

Greater mass of products than initial material

Lesser mass of products than initial material

## Questions 5 of 50

Question:$${C^{14}}$$ is

## Questions 6 of 50

Question:Energy required to separate neutron and proton from the nucleus is called

Bond energy

Nuclear energy

Chemical energy

## Questions 7 of 50

Question:Liquid sodium finds use in nuclear reactors. Its function is

To collect the reaction products

To act as a heat exchanger or coolant

To absorb the neutrons in order to control the chain reaction

To act as a moderator which slows down the neutrons

## Questions 8 of 50

Question:Which is least effective for artificial transmutation

Deuterons

Neutrons

$$\alpha$$-Particle

Protons

## Questions 9 of 50

Question:A radioactive isotope has a half-life of 20 days. If 100 gm of the substance is taken, the weight of the isotope remaining after 40 days is

25 gm

2.5 gm

60 gm

40 gm

## Questions 10 of 50

Question:In a fission reaction the nucleus of an element

Loses only some elementary nuclear particles from another nucleus

Captures some elementary nuclear particles from another nucleus

Breaks up into several smaller nuclei

Breaks up into two smaller nuclei with the loss of same elementary nuclear particles

## Questions 11 of 50

Question:The element used for dating the ancient remains is

Ni

C-14

C-12

Rd

## Questions 12 of 50

Question:If radium and chlorine combine to from radium chloride the compound is

## Questions 13 of 50

Question:When a radioactive element emits an electron the daughter element formed will have

Mass number one unit less

Atomic number one unit less

Mass number one unit more

Atomic number one unit more

## Questions 14 of 50

Question:If the amount of radioactive substance is increased three times, the number of atoms disintegrated per unit time would

Be double

Be triple

Remain one third

Not change

## Questions 15 of 50

Question:The end product of $$(4n+2)$$ radioactive disintegration series is

$$_{82}P{b^{208}}$$

$$_{82}P{b^{206}}$$

$$_{82}P{b^{207}}$$

$$_{83}B{i^{210}}$$

## Questions 16 of 50

Question:The element $$_{{\rm{9}}0}T{h^{{\rm{232}}}}$$ belongs to thorium series. Which of the following will act as the end product of the series

$$_{{\rm{82}}}P{b^{{\rm{2}}0{\rm{8}}}}$$

$$_{{\rm{82}}}B{i^{{\rm{2}}0{\rm{9}}}}$$

$$_{{\rm{82}}}P{b^{{\rm{2}}0{\rm{6}}}}$$

$$_{{\rm{82}}}P{b^{{\rm{2}}0{\rm{7}}}}$$

## Questions 17 of 50

Question:The reaction which disintegrates neutron is or neutron is emitted (which completes first)

$$_{96}A{m^{240}}{+_2}H{e^4}\to{_{97}}B{k^{244}}+{_{+1}}{e^0}$$

$$_{15}{P^{30}}\to{\;_{14}}S{i^{30}}+{\;_1}{e^0}$$

$$_6{C^{12}}+{\;_1}{H^1}\to{\;_7}{N^{13}}$$

$$_{13}A{l^{27}}+{\;_2}H{e^4}\to{\;_{15}}{P^{30}}$$

## Questions 18 of 50

Question:If $$_{92}{U^{236}}$$ nucleus emits one $$\alpha$$-particle, the remaining nucleus will have

119 neutrons and 119 protons

142 neutrons and 90 protons

144 neutrons and 92 protons

146 neutrons and 90 protons

## Questions 19 of 50

Question:The highest binding energy per nucleon will be for

Fe

$${H_2}$$

$${O_2}$$

U

## Questions 20 of 50

Question:In the Thorium series, $$_{90}Th{^{232}}$$ loses total of 6 $$\alpha$$ -particles and 4 $$\beta$$ -particles in ten stages. The final isotope produced in the series is

$$_{82}P{b^{209}}$$

$$_{83}B{i^{209}}$$

$$_{82}P{b^{208}}$$

$$_{82}P{b^{206}}$$

## Questions 21 of 50

Question:O – 18 isotope of oxygen will have

18 protons

9 protons and 9 neutrons

8 neutrons and 10 protons

10 neutrons and 8 protons

## Questions 22 of 50

Question:Which of the following is an isobaric pair

$$_6{C^{13}},{\,_7}{N^{13}}$$

$$_6{C^{13}},{\,_7}{N^{14}}$$

$$_7{N^{14}},{\,_8}{O^{15}}$$

$$_7{N^{13}},{\,_8}{O^{15}}$$

## Questions 23 of 50

Question:Which of the following statement is false

In chlorine gas, the ratio of $$C{l^{35}}$$ and $$C{l^{37}}$$ is 1 : 3

The hydrogen bomb is based on the principle of nuclear fusion

The atom bomb is based on the principle of nuclear fission

The penetrating power of a proton is less than that of an electron

## Questions 24 of 50

Question:Isotones are elements having

Same mass number but different neutrons

Same atomic number but different neutrons

Same atomic number, mass number and neutrons

Different atomic and mass number but same neutrons

## Questions 25 of 50

Question:If a radioactive isotope with atomic number A and mass number M emits an $$\alpha$$-particle, the atomic number and mass number of that new isotope will become

A – 2, M – 4

A – 2, M

A, M – 2

A – 4, M – 2

## Questions 26 of 50

Question:Which character is different of the two isotopes of an element

Atomic mass

Atomic number

Number of electrons

Number of protons

## Questions 27 of 50

Question:Isotopes were discovered by

Aston

Soddy

Thomson

Millikan

## Questions 28 of 50

Question:Which of the following are iso-electronic

$$C{O_2}$$ and $$NO$$

$$S{O_2}$$ and$$C{O_2}$$

$$CN$$ and $$CO$$

$$N{O_2}$$ and $$C{O_2}$$

## Questions 29 of 50

Question:The radionucleide $$_{90}^{234}Th$$ undergoes two successive $$\beta$$-decays followed by one $$\alpha$$-decay. The atomic number and the mass number respectively of the resulting radionucleide are

92 and 234

94 and 230

90 and 230

92 and 230

## Questions 30 of 50

Question:Hydrogen and deuterium differ in

Reactivity with oxygen

Reactivity with chlorine

Melting point

Reducing action

## Questions 31 of 50

Question:Which of the following nuclides has the magic number of both protons and neutrons

$$_{50}S{n^{115}}$$

$$_{82}P{b^{206}}$$

$$_{82}P{b^{208}}$$

$$_{50}S{n^{118}}$$

## Questions 32 of 50

Question:In the carbon cycle, from which hot stars obtain their energy, the $$_6{C^{14}}$$ nucleus is

Completely converted into energy

Regenerated at the end of the cycle

Combined with oxygen to form carbon monoxide

Broken up into its constituents protons and neutrons

## Questions 33 of 50

Question:Which of the following is the most stable atom

$$Bi$$

$$Al$$

$$U$$

$$Pb$$

## Questions 34 of 50

Question:The positron is discovered by

Pauling

Anderson

Yukawa

Segar

## Questions 35 of 50

Question:In the following reaction, $$x$$ will be $$_{29}C{u^{64}}{\to_{28}}N{i^{64}}+x$$

A proton

An electron

A neutron

A positron

## Questions 36 of 50

Question:Which one out of the following statements is not correct for ortho and para hydrogen

They have different boiling point

Ortho form is more stable than para form

They differ in the spin of their protons

The ratio of ortho to para hydrogen increases with increase in temperature and finally pure ortho form is obtained

## Questions 37 of 50

Question:The $$\alpha$$-particle is identical with

Helium nucleus

Hydrogen nucleus

Electron

Proton

## Questions 38 of 50

Question:If by mistake some radioactive substance gets inside the human body, then from the point of view of radiation damage, the most harmful will be the one which emits

$$\gamma$$-rays

Neutrons

$$\beta$$-particles

$$\alpha$$-particles

## Questions 39 of 50

Question:The radiations from a naturally occurring radio element, as seen after deflection in a magnetic field in one direction, are

Definitely $$\alpha$$-rays

Definitely $$\beta$$-rays

Both $$\alpha$$ and $$\beta$$-rays

Either $$\alpha$$ or $$\beta$$-rays

## Questions 40 of 50

Question:The $$_{88}R{a^{226}}$$ is

n-mesons

u-mesons

## Questions 41 of 50

Question:In the radioactive decay $$_{92}{X^{232}}\to{\,_{89}}{Y^{220}}$$, how many $$\alpha$$ and $$\beta$$- particles are ejected from $$X$$ to form $$Y$$

$$3\alpha$$ and $$3\beta$$

$$5\alpha$$ and $$3\beta$$

$$3\alpha$$ and $$5\beta$$

$$5\alpha$$ and $$5\beta$$

## Questions 42 of 50

Question:Which of the following does not take place by $$\alpha$$- decay

$$_{92}{U^{238}} \to {\,_{90}}T{h^{234}}$$

$$_{90}T{h^{232}} \to {\,_{88}}R{a^{228}}$$

$$_{88}R{a^{226}} \to {\,_{86}}R{n^{222}}$$

$$_{83}B{i^{213}} \to {\,_{84}}P{o^{213}}$$

## Questions 43 of 50

Question:The half-life of a radio isotope is 20 hours. After 60 hours, how much amount will be left behind

1/8

1/4

1/3

1/2

## Questions 44 of 50

Question:Half-life period of a zero order reaction is

Inversely proportional to the concentration

Independent of the concentration

Directly proportional to the initial concentration

Directly proportional to the final concentration

## Questions 45 of 50

Question:The half-life of radium (226) is 1620 years. The time taken to convert 10 grams of radium to 1.25 grams is

810 years

1620 years

3240 years

4860 years

## Questions 46 of 50

Question:Half-life of a radioactive substance is 120 days. After 480 days, 4 gm will be reduced to

2

1

0.5

0.25

## Questions 47 of 50

Question:The half-life of a radioactive element is 6 months. The time taken to reduce its original concentration to its 1/16 value is

1 year

16 years

2 years

8 years

## Questions 48 of 50

Question:In the case of a radio isotope the value of $${T_{1/2}}$$ and l are identical in magnitude. The value is

$$0.693$$

$${(0.693)^{1/2}}$$

$$1/0.693$$

$${(0.693)^2}$$

## Questions 49 of 50

Question:If $${U^{235}}$$ is bombarded with neutrons, atom will split into

Sr + Pb

Cs + Rb

Kr + Cd

Ba + Kr

## Questions 50 of 50

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