State the difference between nuclear fission and nuclear fusion. Find the released energy Q in the given fission process: U 235 92 + n 1 0 → Xe 140 54 + Sr 38 94 + 2 n 1 0 + Q Given: mass of U 235 92 = 235 . 0439 amu mass of Xe 140 54 = 139 . 9054 amu mass of Sr 94 38 = 93 . 9063 amu mass of n 1 0 = 1 . 00867 amu 1 amu = 932 MeV

Nuclear fission is a process of splitting of a heavier nucleus into two lighter nuclei. It generally occurs in elements of high atomic mass. Nuclear fusion is a process of combination of two light nuclei to form a heavier nuclei. It generally occurs in elements of low atomic mass. In both the processes, the total mass of the products is slightly less than the mass of the original nuclei. This difference in mass is converted to energy. Energy = mass of reactant - mass of product × 931 MeV = 235 . 0439 + 1 . 00867 - 139 . 9054 + 93 . 9063 + 3 × 1 . 00867 × 931 MeV = 236 . 05268 - 235 . 8295 × 931 MeV = 0 . 22318 × 931 MeV Energy = 207 . 89217 MeV

Find the energy released when two H 2 1 nuclei fuse together to form a single He 4 2 nucleus. Given, the binding energy per nucleon of H 2 1 and He 4 2 are 1 . 1 MeV and 7 . 0 MeV respectively.

In the given question we have to use the concept of Nuclear fusion and apply it to solve the given question. H 2 1 + H 2 1 → H 2 e 4 + Δ E The binding energy per nucleon of a deuteron =1.1MeV &there4; Total binding energy = 2 × 1 . 1 = 2 . 2 M e V The binding energy per nucleon of a helium nucleus =7MeV &there4; Total binding energy = 4 × 7 = 28 M e V &there4; Hence, energy released Δ E = ( 28 − 2 × 2 . 2 ) = 23 . 6 M e V . Hence, 23.6 MeV will be the correct answer.

Consider the items listed in column I and II below: Column I Column II (i) Breeder reactor (a) Fusion reactors (ii) Energy of a star (b) Controlled chain reaction (iii) Thermal neutrons (c) Fast neutrons (iv) Plasma confinement (d) Thermonuclear fusion The most appropriate matching of items in the two columns is given by

(i) - (b), (ii) - (c), (iii) - (d), (iv) - (a)

(i) - (c), (ii) - (d), (iii) - (b), (iv) - (a)

(i) - (c), (ii) - (b), (iii) - (d), (iv) - (a)

(i) - (d), (ii) - (c), (iii) - (b), (iv) - (a)

EASY

Earn 100

What is nuclear fusion give example?

Important Questions on Structure of Atoms and Nuclei

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

State the difference between nuclear fission and nuclear fusion. Find the released energy $Q$ in the given fission process:

${}_{92}{U^{235}} + {}_{0}{n^{1}} \to {}_{54}{Xe}^{140} + {}_{38}{Sr}^{94} + 2 {}_{0}{n^{1}} + Q$

Given:

mass of ${}_{92}{U^{235}} = 235.0439 amu$

mass of ${}_{54}{Xe}^{140} = 139.9054 amu$

mass of ${}_{38}{Sr}^{94} = 93.9063 amu$

mass of ${}_{0}{n^{1}} = 1.00867 amu$

$1 amu = 932 MeV$

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Explain the red giant stage of a star. Which is the factor that decides the next stage of a star after its red giant stage?

EASY

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

What is the nuclear fusion process ? Give an example of nuclear fusion in nature.

A star converts four helium nuclei into one oxygen nucleus. If masses of helium and oxygen nuclei are $4.0015$ amu and $15.995$ amu respectively , then find the energy released per oxygen nucleus.

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

What kind of nuclear reaction is the source of the sun's energy?

HARD

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Find the energy released when two ${}_{1}{H^{2}}$ nuclei fuse together to form a single ${}_{2}{He}^{4}$ nucleus. Given, the binding energy per nucleon of ${}_{1}{H^{2}}$ and ${}_{2}{He}^{4}$ are $1.1 MeV$ and $7.0 MeV$ respectively.

HARD

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Write the equation of proton-proton cycle in the sun.

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Explain the supernova stage of a star. Mention the main feature of a black hole.

EASY

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

The half-life of a radioactive substance is

30 \min

. The time (in minutes) taken between

40 %

decay and

85 %

decay of the same radioactive substance is

HARD

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Write down different set of proton-proton cycle of fusion reaction in the sun.

EASY

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Write one balanced equation of Nuclear fusion.

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Consider the items listed in column I and II below:

Column I	Column II
(i) Breeder reactor	(a) Fusion reactors
(ii) Energy of a star	(b) Controlled chain reaction
(iii) Thermal neutrons	(c) Fast neutrons
(iv) Plasma confinement	(d) Thermonuclear fusion

The most appropriate matching of items in the two columns is given by

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

An electron, a doubly ionized helium ion

({He}^{+ +})

and proton are having the same kinetic energy. The relation between their respective de-Broglie wavelength

λ_{e}, λ_{{He}^{+ +}}

and

λ_{p}

is :

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Using a nuclear counter the count rate of emitted particles from a radioactive source is measured. At

t = 0

it was

1600

counts per second and

t = 8

seconds it was

100

counts per second. The count rate observed, as counts per second, at

t = 6

seconds is close to:

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Distinguish between nuclear fission and nuclear fusion.

HARD

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

In a radioactive decay chain,

_{90}^{232} Th

nucleus decays to

_{82}^{212} Pb

nucleus. Let

N_{α} and N_{β}

be the number of

α and β^{-}

particles, respectively, emitted in this decay process. Which of the following statements is (are) true?

EASY

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

A radioactive element has a rate of disintegration

10, 000

disintegrations per minute at a particular instant. After four minutes it becomes

2500

disintegrations per minute. The decay constant per minute is

EASY

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

A radioactive nucleus

A

with a half-life

T

, decays into a nucleus

B

. At

t = 0

, there is no nucleus

B

. At some time

t

, the ratio of the number of

B

to that of

A

0.3

. Then,

t

is given by:

(Consider \log_{e} (x) = \log (x))

HARD

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

Explain the source of energy with the help of proton proton cycle. What is the role of cadmium rod in nuclear reactor?

EASY

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

What is meant by pair production and annihilation?

MEDIUM

Physics>Modern Physics>Structure of Atoms and Nuclei>Radioactivity

The Binding energy per nucleon of

{}_{3}^{7}{L i}

and

{}_{2}^{4}{H e}

nucleon are

5.60 M e V

and

7.06 M eV

, respectively. In the nuclear reaction

_{3}^{7} L i +_{1}^{1} H \to_{2}^{4} H e +_{2}^{4} H e + Q

, the value of energy

Q

released is

What is nuclear fusion give example?

Important Questions on Structure of Atoms and Nuclei

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