A neutron in the nucleus decays emitting an electron.

A proton in the nucleus decays emitting an electron.

An electron which is already present within the nucleus is ejected.

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Do alpha particles have discrete energies?

Important Questions on Nuclear Physics

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Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

A nucleus, initially at rest, breaks up into two nuclear fragments with their radii in the ratio

2 : 1 .

Then their velocities will be in the ratio

HARD

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

Carbon $- 11$ decays to boron $- 11$ according to the following formula: ${}_{6}^{11}C \to {}_{5}^{11}B + e^{+} + v_{e} + 0.96 MeV$ .
Assume that positrons $(e^{+})$ produced in the decay combines with free electrons in the atmosphere and annihilate each other almost immediately. Also, assume that the neutrinos $(v_{e})$ are massless and do not interact with the environment. At $t = 0$ , we have $1 μg$ of ${}_{6}^{12}C$ . If the half-life of the decay process is $t_{0}$ , the net energy produced between time, $t = 0$ and $t = 2 t_{0}$ will be nearly,

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

The end product of decay of

_{90} {Th}^{232}

_{82} {Pb}^{208}

. The number of

α

and

β

particles emitted are respectively

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

A nucleus ruptures into two nuclear parts which have their velocity ratio equal to

2 : 1

, What will be the ratio of their nuclear size (nuclear radius):-

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

A nucleus of uranium decays at rest into nuclei of thorium and helium. Then:

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

What happens to the mass number and atomic number of an element when it emits

γ

-radiation

HARD

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

Suppose a

{}_{88}^{226}{R a}

nucleus at rest and in ground state undergoes

α

-decay to a

{}_{86}^{222}{R n}

nucleus in its excited state. The kinetic energy of the emitted

α

particle is found to be

4.44 M e V . {}_{86}^{222}R n

nucleus then goes to its ground state by

γ

-decay. The energy of the emitted

γ

-photon is _______

k e V,

[Given: atomic mass of

_{88}^{226} R a = 226.005 u,

atomic mass of

_{86}^{222} R n = 222.000 u,

atomic mass of

α

particle

= 4.000 u, 1 u = 931 M e V / c^{2}, c

is speed of the light]

MEDIUM

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

For nuclei with mass number close to

119

and

238

, the binding energies per nucleon are approximately

7.6 MeV

and

8.6 MeV

, respectively. If a nucleus of mass number

238

breaks into two nuclei of nearly equal masses, what will be the approximate amount of energy released in the process of fission?

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

A decay chain of the nucleus

{}_{92}^{238}U

involves eight

α

-decays and six

β

-decays. The final nucleus at the end of the process will be

MEDIUM

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

The beta particles of a radioactive metal originate from-

MEDIUM

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

{}_{90}^{232}{Th}

emits

6 α

and

4 β

particles and gets converted into a lead. The mass number and atomic number of lead is _____

HARD

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

A plot of the number of neutrons

(N)

against the number of protons

(P)

of the stable nuclei exhibits upwards deviation from linearity for atomic number,

Z > 20

. For an unstable nucleus having

\frac{N}{P}

ratio less than

1

, the possible mode(s) of decay is (are):

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

During a

β

- decay

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Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

The number of

α

-particles emitted during the radioactive decay chain from

{}_{88}^{226}{Ra}

and ending at

{}_{82}^{206}{Pb}

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

Assertion (A) : Neutrino is chargeless and possesses spin.

Reason $(R) :$ Neutrino exists inside the nucleus.

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

The atomic number and the mass number of an atom remains unchanged when it emits

HARD

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

Originally the radioactive beta decay was thought as a decay of a nucleus with the emission of electrons only (Case I) . However, in addition to the electron, another (nearly) massless and electrically neutral particle is also emitted (Case II). Based on the figure below, which of the following is correct?

Question Image

EASY

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

A nuclear decay is possible if the mass of the parent nucleus exceeds the total mass of the decay particles. If

M (A, Z)

denotes the mass of a single neutral atom of an element with mass number A and atomic number Z, then the minimal condition that the

β

decay,

X_{Z}^{A} \to Y_{Z + 1}^{A} + β^{-} + \bar{v_{e}}

, will occur is (

m_{e}

denotes the mass of the

β

particle and the neutrino mass

m_{v}

can be neglected):

HARD

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

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?

MEDIUM

Physics>Modern Physics>Nuclear Physics>Theory of Alpha Decay

In which sequence the radioactive radiations are emitted in the following nuclear reaction?

${}_{Z}X^{A} \to {}_{Z + 1}Y^{A} \to {}_{Z - 1}K^{A - 4} \to {}_{Z - 1}K^{A - 4}$

Do alpha particles have discrete energies?

Important Questions on Nuclear Physics

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