# Nuclear Chemistry Test 1

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

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

Geiger

Wilson

Rutherford

Soddy

## Questions 2 of 50

Question:Artificial elements have been prepared by bombardment reactions in high energy accelerators. What is the mass number of the element X produced in the following nuclear reaction $$_{95}^{249}Cf+_7^{15}N{\to_{105}}X+4_0^1n$$

261

264

260

257

## Questions 3 of 50

Question:The proper rays for radiocarbon dating are

UV-rays

IR-rays

Cosmic rays

X-rays

## Questions 4 of 50

Question:$$_1{H^2}+{\,_1}{H^2}\to{\,_2}H{e^3}+{\,_0}{n^1}$$. Above nuclear reaction is called

Nuclear fission

Nuclear fusion

Artificial transmutation

Spontaneous disintegration

## Questions 5 of 50

Question:Large energy released in an atomic bomb explosion is mainly due to

Products having a lesser mass than initial substance

Conversion of heavier to lighter atoms

Release of neutrons

Release of electrons

## Questions 6 of 50

Question:The reaction $$_1{H^2}+{\,_1}{H^3}\to{\,_2}H{e^4}+{\,_0}{n^1}+$$energy represents

Nuclear fission

Nuclear fusion

Artificial disintegration

Transmutation of element

## Questions 7 of 50

Question:$$C-14$$ is used in carbon dating of dead objects because

Its half-life is $${10^3}$$ years

Its half-life is $${10^4}$$ years

It is found in nature abundantly and in definite ratio

It is found in dead animals abundantly

## Questions 8 of 50

Question:A radioactive element resembling iodine in properties is

Astatine

Thorium

## Questions 9 of 50

Question:In a nuclear reactor, chain reaction is controlled by introducing

Iron rod

Graphite rod

Platinum rod

## Questions 10 of 50

Question:In atomic reactors, graphite is used as a

Lubricant

Moderator to slow down neutrons

Fuel

Liner of the reactor

## Questions 11 of 50

Question:Radioactive disintegration differs from a chemical change in being

An exothermic change

A spontaneous process

A nuclear process

A unimolecular first order reaction

## Questions 12 of 50

Question:$$_{92}^{238}U$$ emits 8 $$\alpha$$-particles and 6 $$\beta$$-particles. The neutron/proton ratio in the product nucleus is

60/41

61/40

62/41

61/42

## Questions 13 of 50

Question:$$_{13}^{27}Al$$ is a stable isotope. $$_{13}^{29}Al$$ is expected to disintegrate by

$$\alpha$$-emission

$$\beta$$-emission

Positron emission

Proton emission

## Questions 14 of 50

Question:An isotope $$_Y{A^X}$$ undergoes a series of $$m$$ alpha and $$n$$ beta disintegration to form a stable isotope $$_{Y-10}{B^{X-32}}$$. The values of $$m$$ and $$n$$ are respectively

6 and 8

8 and 10

5 and 8

8 and 6

## Questions 15 of 50

Question:What is the symbol for the nucleus remaining after $$_{20}C{a^{42}}$$ undergoes $$\beta$$-emission

$$_{21}C{a^{42}}$$

$$_{20}S{c^{42}}$$

$$_{21}S{c^{42}}$$

$$_{21}S{c^{41}}$$

## Questions 16 of 50

Question:When a radioactive nucleus emits an $$\alpha$$-particle, the mass of the atom

Increases and its at. number decreases

Decreases and its at. number decreases

Decreases and its at. number increases

Remains same and its at. number decreases

## Questions 17 of 50

Question:If the quantity of a radioactive element is doubled, then its rate of disintegration per unit time will be

Unchanged

Reduced to half

Increased by $$\sqrt2$$times

Doubled

## Questions 18 of 50

Question:The number of$$\alpha$$ and $$\beta$$ -particles emitted during the transformation of $$_{90}T{h^{232}}$$ to $$_{82}{P^{208}}$$ are respectively

4, 2

2, 2

8, 6

6, 4

## Questions 19 of 50

Question:The disintegration constant of radium with half-life 1600 years is

$$2.12\times{10^{-4}}yea{r^{-1}}$$

$$4.33\times{10^{-4}}yea{r^{-1}}$$

$$3.26\times{10^{-3}}yea{r^{-1}}$$

$$4.33\times{10^{-12}}yea{r^{-1}}$$

## Questions 20 of 50

Question:The number of $$\alpha$$ and $$\beta-$$particles emitted in the nuclear reaction $$_{92}{U^{238}}{\to_{90}}T{h^{234}}{\to_{91}}P{a^{234}}$$are respectively

1 and 1

1 and 2

2 and 1

2 and 2

## Questions 21 of 50

Question:Radioactive isotopes that have an excessive neutron/proton ratio generally exhibit

$${e^-}$$ emission

$$_2H{e^4}$$ emission

$${e^+}$$ emission

K -electron capture

## Questions 22 of 50

Question:Atomic weights of carbon, nitrogen and oxygen are 12, 14 and 16 respectively. An atom of atomic weight 14 and nuclear charge + 6 is an isotope of

Oxygen

Carbon

Nitrogen

None of these

## Questions 23 of 50

Question:Which of the following is an isotonic pair

$$_{19}^{40}K,\,_{20}^{40}Ca$$

$$_{19}^{39}K,\,_{20}^{40}Ca$$

$$_{18}^{33}Ar,\,_{\,18}^{40}Ar$$

$$_{18}^{40}Ar,\,_{\,20}^{40}Ca$$

## Questions 24 of 50

Question:$$_6{C^{11}}$$ and $$_5{B^{11}}$$ are referred as

Nuclear isomers

Isobars

Isotopes

Fission products

## Questions 25 of 50

Question:Two nuclei which are not identical but have the same number of nucleons represent

Isotopes

Isobars

Isotones

None of the three

## Questions 26 of 50

Question:The $$\beta$$-decay of $$_{11}N{a^{24}}$$ produces an isotope of

Mg

Na

Al

Ne

## Questions 27 of 50

Question:On bombarding $$_7{N^{14}}$$ with $$\alpha$$-particles, the nuclei of the product formed after the release of a proton will be or In nuclear reaction $$_7{N^{14}}+{\,_2}H{e^4}{\to_Z}{X^A}{+_1}{H^1}$$, the term $$_Z{X^A}$$ represents

$$_8{O^{17}}$$

$$_9{F^{18}}$$

$$_9{F^{17}}$$

$$_8{O^{18}}$$

## Questions 28 of 50

Question:Nuclear energy is based on the conversion of

Protons into neutrons

Mass into energy

Neutrons into protons

## Questions 29 of 50

Question:In the nuclear reaction $$_{12}M{g^{24}}{+_2}H{e^4}{=_0}{n^1}+?$$ The product nucleus is

$$_{13}A{l^{27}}$$

$$_{14}S{i^{27}}$$

$$_{13}A{l^{28}}$$

$$_{12}M{g^{25}}$$

## Questions 30 of 50

Question:$$_6{C^{14}}$$ is formed from $$_7{N^{14}}$$ in the upper atmosphere by the action of the fundamental particle

Positron

Neutron

Electron

Proton

## Questions 31 of 50

Question:In terms of energy 1 a. m.u. is equal to

100 J

931.1 MeV

931.1 kcal

$${10^7}$$erg

## Questions 32 of 50

Question:Positron is

Electron with +ve charge

A helium nucleus

A nucleus with two protons

A nucleus with one neutron and one proton

## Questions 33 of 50

Question:Which of the following particle is emitted in the reaction $$_{13}A{l^{27}}{+_2}H{e^4}{\to_{14}}{P^{30}}+.....$$

$$_0{n^1}$$

$$_{-1}{e^0}$$

$$_1{H^1}$$

$$_1{H^2}$$

## Questions 34 of 50

Question:Which of the following sub-atomic particles is not present in an atom

Neutron

Proton

Electron

Positron

## Questions 35 of 50

Question:Which statement is incorrect

$$\alpha$$-rays have more penetrating power than $$\beta$$-rays

$$\alpha$$-rays have less penetrating power than $$\gamma$$-rays

$$\beta$$-rays have less penetrating power than $$\gamma$$-rays

$$\beta$$-rays have more penetrating power than $$\alpha$$-rays

## Questions 36 of 50

Question:The velocity of $$\alpha$$-rays is approximately

Equal to that of the velocity of light

1/10 of the velocity of light

10 times more than the velocity of light

Uncomparable to the velocity of light

## Questions 37 of 50

Question:Choose the element which is not radioactive

$$Cm$$

$$No$$

$$Mo$$

$$Md$$

## Questions 38 of 50

Question:A magnet will cause the greatest deflection of

$$\gamma$$-rays

$$\beta$$-rays

$$\alpha$$-rays

Neutrons

## Questions 39 of 50

Question:The charge on gamma rays is

Zero

1

1

2

## Questions 40 of 50

Question:A nuclear reaction is accompanied by loss of mass equivalent to $$0.01864\;amu$$. Energy liberated is

$$931\;MeV$$

$$186.6\;MeV$$

$$17.36\;MeV$$

$$460\;MeV$$

## Questions 41 of 50

Question:$$10gm$$ of a radioactive substance is reduced to $$1.25gm$$ after 15 days. Its $$1kg$$ mass will reduce (in how many days) to $$500gm$$ in

500 days

125 days

25 days

5 days

## Questions 42 of 50

Question:A radioactive isotope having a half-life of 3 days was received after 12 days. It was found that there were 3 gm of the isotope in the container. The initial weight of the isotope when packed was

12 gm

24 gm

36 gm

48 gm

## Questions 43 of 50

Question:What is the value of decay constant of a compound having half-life time $${T_{1/2}}=2.95$$ days

$$2.7\times{10^{-5}}{s^{-1}}$$

$$2.7\times{10^6}{s^{-1}}$$

$$2.7\times{10^{-6}}{s^{-1}}$$

$$3\times{10^5}{s^{-1}}$$

## Questions 44 of 50

Question:What kind of radioactive decay does not lead to the formation of a daughter nucleus that is an isobar of the parent nucleus

$$\alpha$$ -Particle

$$\beta$$ - Particle

Positron

Electron capture

## Questions 45 of 50

Question:For a radioactive substance with half-life period 500 years, the time for complete decay of 100 milligram of it would be

1000 years

$$100\times500$$ years

500 years

Infinite time

## Questions 46 of 50

Question:A substance of which one gram is taken, after half-life time what fraction of it is left ?

$$\frac{1}{4}$$

$$\frac{1}{8}$$

$$\frac{1}{2}$$

$$\frac{1}{{32}}$$

## Questions 47 of 50

Question:Given that a radioactive species decays according to exponential law $$N={N_0}{e^{-\lambdat}}$$. The half-life of the species is

$$\lambda$$

$$No$$

$$\lambda/\ln2$$

$$\ln2/\lambda$$

## Questions 48 of 50

Question:Half-life of a radioactive disintegration (A $$\to$$B) having rate constant $$231\,{\sec^{-1}}$$ is

$$3.0\times{10^{-2}}$$ sec

$$3.0\times{10^{-3}}$$ sec

$$3.3\times{10^{-2}}$$ sec

$$3.3\times{10^{-3}}$$ sec

## Questions 49 of 50

Question:A radioactive isotope decays at such a rate that after 192 minutes only $$1/16$$ of the original amount remains. The half-life of the radioactive isotope is

32 min

48 min

12 min

24 min

## Questions 50 of 50

Question:Rate constant for a reaction is $$\lambda$$. Average life is representative by

$$1/\lambda$$
$${\rm{In}}2/\lambda$$
$$\frac{\lambda}{{\sqrt2}}$$
$$\frac{{0.693}}{\lambda}$$