Question 13.1:

Two stable isotopes of lithium        and        have respective abundances of 7.5% and 92.5%. These isotopes have masses 6.01512 u and 7.01600 u, respectively. Find the atomic mass of lithium.

Boron has two stable isotopes,       and      . Their respective masses are 10.01294 u and 11.00931 u, and the atomic mass of boron is 10.811 u. Find the abundances of                                      and

.

Answer

Mass of lithium isotope , m₁ = 6.01512 u Mass of lithium isotope , m₂ = 7.01600 u Abundance of , η₁= 7.5%

Abundance of      , η₂= 92.5%

The atomic mass of lithium atom is given as:

Mass of boron isotope , m₁ = 10.01294 u Mass of boron isotope , m₂ = 11.00931 u Abundance of , η₁ = x%

Abundance of       , η₂= (100 − x)%

Atomic mass of boron, m = 10.811 u

The atomic mass of boron atom is given as:

And 100 − x = 80.11%

Hence, the abundance of

Question 13.2:

is 19.89% and that of       is 80.11%.

The three stable isotopes of neon:                  and          have respective abundances of 90.51%, 0.27% and 9.22%. The atomic masses of the three isotopes are 19.99 u, 20.99 u and 21.99 u, respectively. Obtain the average atomic mass of neon.

Answer

Atomic mass of         , m₁= 19.99 u Abundance of , η₁ = 90.51% Atomic mass of               , m₂ = 20.99 u

Abundance of         , η₂ = 0.27%

Atomic mass of         , m₃ = 21.99 u Abundance of , η₃ = 9.22%

The average atomic mass of neon is given as:

Question 13.3:

Obtain the binding energy (in MeV) of a nitrogen nucleus  , given

=14.00307 u

Answer

Atomic mass of nitrogen            , m = 14.00307 u

A nucleus of nitrogen         contains 7 protons and 7 neutrons.

Hence, the mass defect of this nucleus, Δm = 7m_H + 7m_n − m

Where,

Mass of a proton, m_H = 1.007825 u Mass of a neutron, m_n= 1.008665 u

∴Δm = 7 × 1.007825 + 7 × 1.008665 − 14.00307

= 7.054775 + 7.06055 − 14.00307

= 0.11236 u

But 1 u = 931.5 MeV/c²

∴Δm = 0.11236 × 931.5 MeV/c²

Hence, the binding energy of the nucleus is given as:

E_b = Δmc²

Where,

c = Speed of light

∴E_b = 0.11236 × 931.5

= 104.66334 MeV

Hence, the binding energy of a nitrogen nucleus is 104.66334 MeV.

Question 13.4:

Obtain the binding energy of the nuclei         and          in units of MeV from the following data:

 = 55.934939 u = 208.980388 u

Answer

Atomic mass of        , m₁ = 55.934939 u

nucleus has 26 protons and (56 − 26) = 30 neutrons

Hence, the mass defect of the nucleus, Δm = 26 × m_H + 30 × m_n − m₁

Where,

Mass of a proton, m_H = 1.007825 u Mass of a neutron, m_n = 1.008665 u

∴Δm = 26 × 1.007825 + 30 × 1.008665 − 55.934939

= 26.20345 + 30.25995 − 55.934939

= 0.528461 u

But 1 u = 931.5 MeV/c²

∴Δm = 0.528461 × 931.5 MeV/c²

The binding energy of this nucleus is given as:

E_b1 = Δmc²

Where,

c = Speed of light

∴E_b1 = 0.528461 × 931.5

= 492.26 MeV

Average binding energy per nucleon Atomic mass of       , m₂ = 208.980388 u

nucleus has 83 protons and (209 − 83) 126 neutrons.

Hence, the mass defect of this nucleus is given as:

Δm' = 83 × m_H + 126 × m_n − m₂

Where,

Mass of a proton, m_H = 1.007825 u Mass of a neutron, m_n = 1.008665 u

∴Δm' = 83 × 1.007825 + 126 × 1.008665 − 208.980388

= 83.649475 + 127.091790 − 208.980388

= 1.760877 u

But 1 u = 931.5 MeV/c²

∴Δm' = 1.760877 × 931.5 MeV/c²

Hence, the binding energy of this nucleus is given as:

E_b2 = Δm'c²

= 1.760877 × 931.5

= 1640.26 MeV

Average bindingenergy per nucleon =

Question 13.5:

A given coin has a mass of 3.0 g. Calculate the nuclear energy that would be required to separate all the neutrons and protons from each other. For simplicity assume that the coin

is entirely made of         atoms (of mass 62.92960 u).

Answer

Mass of a copper coin, m’ = 3 g

Atomic mass of            atom, m = 62.92960 u

The total number of            atoms in the coin

Where,

N_A = Avogadro’s number = 6.023 × 10²³ atoms /g

Mass number = 63 g

nucleus has 29 protons and (63 − 29) 34 neutrons

∴Mass defect of this nucleus, Δm' = 29 × m_H + 34 × m_n − m

Where,

Mass of a proton, m_H = 1.007825 u Mass of a neutron, m_n = 1.008665 u

∴Δm' = 29 × 1.007825 + 34 × 1.008665 − 62.9296

= 0.591935 u

Mass defect of all the atoms present in the coin, Δm = 0.591935 × 2.868 × 10²²

= 1.69766958 × 10²² u

But 1 u = 931.5 MeV/c²

∴Δm = 1.69766958 × 10²² × 931.5 MeV/c²

Hence, the binding energy of the nuclei of the coin is given as:

E_b= Δmc²

= 1.69766958 × 10²² × 931.5

= 1.581 × 10²⁵ MeV

But 1 MeV = 1.6 × 10⁻¹³ J

E_b = 1.581 × 10²⁵ × 1.6 × 10⁻¹³

= 2.5296 × 10¹² J

This much energy is required to separate all the neutrons and protons from the given coin.

Question 13.6:

Write nuclear reaction equations for

α-decay of           (ii) α-decay of

β⁻-decay of  (iv) β⁻-decay of

(v) β⁺-decay of        (vi) β⁺-decay of

(vii) Electron capture of

Answer

α is a nucleus of helium             and β is an electron (e⁻ for β⁻ and e⁺ for β⁺). In every α-

decay, there is a loss of 2 protons and 4 neutrons. In every β⁺-decay, there is a loss of 1 proton and a neutrino is emitted from the nucleus. In every β⁻-decay, there is a gain of 1 proton and an antineutrino is emitted from the nucleus.

For the given cases, the various nuclear reactions can be written as:

Question 13.7:

A radioactive isotope has a half-life of T years. How long will it take the activity to reduce to a) 3.125%, b) 1% of its original value?

Answer

Half-life of the radioactive isotope = T years Original amount of the radioactive isotope = N₀

After decay, the amount of the radioactive isotope = N

It is given that only 3.125% of N₀ remains after decay. Hence, we can write:

Where,

λ = Decay constant

t = Time

Hence, the isotope will take about 5T years to reduce to 3.125% of its original value.

After decay, the amount of the radioactive isotope = N

It is given that only 1% of N₀ remains after decay. Hence, we can write:

Since, λ = 0.693/T

Hence, the isotope will take about 6.645T years to reduce to 1% of its original value.

Question 13.8:

The normal activity of living carbon-containing matter is found to be about 15 decays per minute for every gram of carbon. This activity arises from the small proportion of

radioactive       present with the stable carbon isotope       . When the organism is dead, its interaction with the atmosphere (which maintains the above equilibrium activity)

ceases and its activity begins to drop. From the known half-life (5730 years) of       , and the measured activity, the age of the specimen can be approximately estimated. This is the

principle of       dating used in archaeology. Suppose a specimen from Mohenjodaro gives an activity of 9 decays per minute per gram of carbon. Estimate the approximate age of the Indus-Valley civilisation.

Answer

Decay rate of living carbon-containing matter, R = 15 decay/min

Let N be the number of radioactive atoms present in a normal carbon- containing matter.

Half life of      ,       = 5730 years

The decay rate of the specimen obtained from the Mohenjodaro site:

R' = 9 decays/min

Let N' be the number of radioactive atoms present in the specimen during the Mohenjodaro period.

Therefore, we can relate the decay constant, λand time, t as:

Hence, the approximate age of the Indus-Valley civilisation is 4223.5 years.

Question 13.9:

Obtain the amount of         necessary to provide a radioactive source of 8.0 mCi strength. The half-life of  is 5.3 years.

Answer

The strength of the radioactive source is given as:

Where,

N = Required number of atoms

Half-life of        ,       = 5.3 years

= 5.3 × 365 × 24 × 60 × 60

= 1.67 × 10⁸ s

For decay constant λ, we have the rate of decay as:

Where, λ

For           :

Mass of 6.023 × 10²³ (Avogadro’s number) atoms = 60 g

∴Mass of                    atoms

Hence, the amount of

Question 13.10:

necessary for the purpose is 7.106 × 10⁻⁶ g.

The half-life of        is 28 years. What is the disintegration rate of 15 mg of this isotope?

Answer

Half life of        ,      = 28 years

= 28 × 365 × 24 × 60 × 60

= 8.83 × 10⁸ s

Mass of the isotope, m = 15 mg

Rate of disintegration,   Where,

λ = Decay constant

Hence, the disintegration rate of 15 mg of the given isotope is 7.878 × 10¹⁰ atoms/s.

Question 13.11:

Obtain approximately the ratio of the nuclear radii of the gold isotope silver isotope           .

Answer

and the

Nuclear radius of the gold isotope              = R_Au

Nuclear radius of the silver isotope              = R_Ag

Mass number of gold, A_Au = 197 Mass number of silver, A_Ag = 107

The ratio of the radii of the two nuclei is related with their mass numbers as:

Hence, the ratio of the nuclear radii of the gold and silver isotopes is about 1.23.

Question 13.12:

Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of (a) and (b)        .

Given                 = 226.02540 u,                 = 222.01750 u,

 = 220.01137 u, = 216.00189 u.

Answer

Alpha particle decay of           emits a helium nucleus. As a result, its mass number reduces to (226 − 4) 222 and its atomic number reduces to (88 − 2) 86. This is shown in the following nuclear reaction.

Q-value of

emitted α-particle = (Sum of initial mass − Sum of final mass) c²

Where,

Q-value = [226.02540 − (222.01750 + 4.002603)] u c²

= 0.005297 u c²

But 1 u = 931.5 MeV/c²

∴Q = 0.005297 × 931.5 ≈ 4.94 MeV

Kinetic energy of the α-particle

Alpha particle decay of              is shown by the following nuclear reaction.

It is given that:

Mass of              = 220.01137 u

Mass of             = 216.00189 u

∴Q-value =

≈ 641 MeV

Kinetic energy of the α-particle

= 6.29 MeV

Question 13.13:

The radionuclide ¹¹C decays according to

The maximum energy of the emitted positron is 0.960 MeV.

Given the mass values:

calculate Q and compare it with the maximum energy of the positron emitted

Answer

The given nuclear reaction is:

Atomic mass of             = 11.011434 u Atomic mass of

Maximum energy possessed by the emitted positron = 0.960 MeV

The change in the Q-value (ΔQ) of the nuclear masses of the       nucleus is given as:

Where,

m_e = Mass of an electron or positron = 0.000548 u

c = Speed of light

m’ = Respective nuclear masses

If atomic masses are used instead of nuclear masses, then we have to add 6 m_e in the case

of      and 5 m_e in the case of      .

Hence, equation (1) reduces to:

∴ΔQ = [11.011434 − 11.009305 − 2 × 0.000548] c²

= (0.001033 c²) u

But 1 u = 931.5 Mev/c²

∴ΔQ = 0.001033 × 931.5 ≈ 0.962 MeV

The value of Q is almost comparable to the maximum energy of the emitted positron.

Question 13.14:

The nucleus         decays by      emission. Write down the     decay equation and

determine the maximum kinetic energy of the electrons emitted. Given that:

= 22.994466 u

= 22.989770 u.

Answer

In       emission, the number of protons increases by 1, and one electron and an antineutrino are emitted from the parent nucleus.

emission of the nucleus          is given as:

It is given that:

Atomic mass of                = 22.994466 u

Atomic mass of                = 22.989770 u

Mass of an electron, m_e = 0.000548 u

Q-value of the given reaction is given as:

There are 10 electrons in          and 11 electrons in         . Hence, the mass of the electron

is cancelled in the Q-value equation.

The daughter nucleus is too heavy as compared to      and    . Hence, it carries negligible energy. The kinetic energy of the antineutrino is nearly zero. Hence, the maximum kinetic energy of the emitted electrons is almost equal to the Q-value, i.e., 4.374 MeV.

Question 13.15:

The Q value of a nuclear reaction A + b → C + d is defined by

Q = [ m_A+ m_b− m_C− m_d]c² where the masses refer to the respective nuclei. Determine from the given data the Q-value of the following reactions and state whether the reactions are exothermic or endothermic.

Atomic masses are given to be

Answer

The given nuclear reaction is:

It is given that:

Atomic mass

Atomic mass Atomic mass

According to the question, the Q-value of the reaction can be written as:

The negativeQ-value of the reaction shows that the reaction is endothermic.

The given nuclear reaction is:

It is given that:

Atomic mass of    Atomic mass of   Atomic mass of   The Q-value of this reaction is given as:

The positive Q-value of the reaction shows that the reaction is exothermic.

Question 13.16:

. Is the

n

and                                   .

Answer

The fission of        can be given as:

It is given that:

Atomic mass of               = 55.93494 u Atomic mass of

The Q-value of this nuclear reaction is given as:

The Q-value of the fission is negative. Therefore, the fission is not possible energetically. For an energetically-possible fission reaction, the Q-value must be positive.

Question 13.17:

The fission properties of          are very similar to those of        .

The average energy released per fission is 180 MeV. How much energy, in MeV, is released if all the atoms in 1 kg of pure                                     undergo fission?

Answer

Average energy released per fission of          ,

Amount of pure           , m = 1 kg = 1000 g N_A= Avogadro number = 6.023 × 10²³

Mass number of         = 239 g

1 mole of            contains N_A atoms.

∴m g of            contains

∴Total energy released during the fission of 1 kg of          is calculated as:

Hence,                             is released if all the atoms in 1 kg of pure fission.

Question 13.18:

undergo

A 1000 MW fission reactor consumes half of its fuel in 5.00 y. How much         did it

contain initially? Assume that the reactor operates 80% of the time, that all the energy

generated arises from the fission of         and that this nuclide is consumed only by the fission process.

Answer

Half life of the fuel of the fission reactor,  years

= 5 × 365 × 24 × 60 × 60 s

We know that in the fission of 1 g of         nucleus, the energy released is equal to 200 MeV.

1 mole, i.e., 235 g of  contains 6.023 × 10²³ atoms.

∴1 g          contains

The total energy generated per gram of        is calculated as:

The reactor operates only 80% of the time.

Hence, the amount of         consumed in 5 years by the 1000 MW fission reactor is calculated as:

∴Initial amount of         = 2 × 1538 = 3076 kg

Question 13.19:

How long can an electric lamp of 100W be kept glowing by fusion of 2.0 kg of deuterium? Take the fusion reaction as

Answer

The given fusion reaction is:

Amount of deuterium, m = 2 kg

1 mole, i.e., 2 g of deuterium contains 6.023 × 10²³ atoms.

∴2.0 kg of deuterium contains

It can be inferred from the given reaction that when two atoms of deuterium fuse, 3.27 MeV energy is released.

∴Total energy per nucleus released in the fusion reaction:

Power of the electric lamp, P = 100 W = 100 J/s

Hence, the energy consumed by the lamp per second = 100 J

The total time for which the electric lamp will glow is calculated as:

Question 13.20:

Calculate the height of the potential barrier for a head on collision of two deuterons. (Hint: The height of the potential barrier is given by the Coulomb repulsion between the two deuterons when they just touch each other. Assume that they can be taken as hard spheres of radius 2.0 fm.)

Answer

When two deuterons collide head-on, the distance between their centres, d is given as: Radius of 1^st deuteron + Radius of 2^nd deuteron

Radius of a deuteron nucleus = 2 fm = 2 × 10⁻¹⁵ m

∴d = 2 × 10⁻¹⁵ + 2 × 10⁻¹⁵ = 4 × 10⁻¹⁵ m

Where,

= Permittivity of free space

Hence, the height of the potential barrier of the two-deuteron system is

360 keV.

Question 13.21:

From the relation R = R₀A¹/³, where R₀ is a constant and A is the mass number of a nucleus, show that the nuclear matter density is nearly constant (i.e. independent of A).

Answer

We have the expression for nuclear radius as:

R = R₀A¹/³

Where,

R₀ = Constant.

A = Mass number of the nucleus

Nuclear matter density,  Let m be the average mass of the nucleus.

Hence, mass of the nucleus = mA

Hence, the nuclear matter density is independent of A. It is nearly constant.

Question 13.22:

For the       (positron) emission from a nucleus, there is another competing process known as electron capture (electron from an inner orbit, say, the K−shell, is captured by the nucleus and a neutrino is emitted).

Show that if       emission is energetically allowed, electron capture is necessarily allowed but not vice−versa.

Answer

Let the amount of energy released during the electron capture process be Q₁. The nuclear reaction can be written as:

Let the amount of energy released during the positron capture process be Q₂. The nuclear reaction can be written as:

= Nuclear mass of

= Nuclear mass of

= Atomic mass of

= Atomic mass of

m_e = Mass of an electron

c = Speed of light

Q-value of the electron capture reaction is given as:

Q-value of the positron capture reaction is given as:

It can be inferred that if Q₂ > 0, then Q₁ > 0; Also, if Q₁> 0, it does not necessarily mean that Q₂ > 0.

In other words, this means that if      emission is energetically allowed, then the electron capture process is necessarily allowed, but not vice-versa. This is because the Q-value must be positive for an energetically-allowed nuclear reaction.

Question 13.23:

In a periodic table the average atomic mass of magnesium is given as 24.312 u. The average value is based on their relative natural abundance on earth. The three isotopes

and their masses are          (23.98504u),           (24.98584u) and           (25.98259u). The

natural abundance of          is 78.99% by mass. Calculate the abundances of other two isotopes.

Answer

Average atomic mass of magnesium, m = 24.312 u

Mass of magnesium isotope         , m₁ = 23.98504 u

Mass of magnesium isotope Mass of magnesium isotope

, m₂ = 24.98584 u

, m₃ = 25.98259 u

Abundance of         , η₁= 78.99% Abundance of   , η₂ = x%

Hence, abundance of         , η₃ = 100 − x − 78.99% = (21.01 − x)%

We have the relation for the average atomic mass as:

Hence, the abundance of

Question 13.24:

is 9.3% and that of           is 11.71%.

The neutron separation energy is defined as the energy required to remove a neutron from

the nucleus. Obtain the neutron separation energies of the nuclei          and following data:

= 39.962591 u

) = 40.962278 u

= 25.986895 u

) = 26.981541 u

Answer

from the

For For

A neutron          is removed from a          nucleus. The corresponding nuclear reaction can be written as:

It is given that:

Mass                = 39.962591 u

Mass               ) = 40.962278 u

Mass              = 1.008665 u

The mass defect of this reaction is given as:

Δm =

∴Δm = 0.008978 × 931.5 MeV/c²

Hence, the energy required for neutron removal is calculated as:

For        , the neutron removal reaction can be written as:

It is given that:

Mass                = 26.981541 u

Mass               = 25.986895 u

The mass defect of this reaction is given as:

Hence, the energy required for neutron removal is calculated as:

Question 13.25:

A source contains two phosphorous radio nuclides       (T_{1/2 =} 14.3d) and       (T_1/2 =

25.3d). Initially, 10% of the decays come from      . How long one must wait until 90% do so?

Answer

Half life of      , T_{1/2 =} 14.3 days Half life of          , T’_1/2 = 25.3 days

nucleus decay is 10% of the total amount of decay.

The source has initially 10% of       nucleus and 90% of       nucleus.

Suppose after t days, the source has 10% of       nucleus and 90% of       nucleus.

Initially:

Number of       nucleus = N

Number of       nucleus = 9 N

Finally:

Number of Number of

For        nucleus, we can write the number ratio as:

For       , we can write the number ratio as:

On dividing equation (1) by equation (2), we get:

Hence, it will take about 208.5 days for 90% decay of         .

Question 13.26:

Under certain circumstances, a nucleus can decay by emitting a particle more massive

than an α-particle. Consider the following decay processes:

Calculate the Q-values for these decays and determine that both are energetically allowed.

Answer

Take a       emission nuclear reaction:

We know that:

Mass of           m₁ = 223.01850 u

Mass of           m₂ = 208.98107 u Mass of , m₃ = 14.00324 u

Hence, the Q-value of the reaction is given as:

Q = (m₁ − m₂ − m₃) c²

= (223.01850 − 208.98107 − 14.00324) c²

= (0.03419 c²) u

But 1 u = 931.5 MeV/c²

∴Q = 0.03419 × 931.5

= 31.848 MeV

Hence, the Q-value of the nuclear reaction is 31.848 MeV. Since the value is positive, the reaction is energetically allowed.

Now take a         emission nuclear reaction:

We know that:

Mass of           m₁ = 223.01850

Mass of           m₂ = 219.00948 Mass of    , m₃ = 4.00260

Q-value of this nuclear reaction is given as:

Q = (m₁ − m₂ − m₃) c²

= (223.01850 − 219.00948 − 4.00260) C²

= (0.00642 c²) u

= 0.00642 × 931.5 = 5.98 MeV

Hence, the Q value of the second nuclear reaction is 5.98 MeV. Since the value is positive, the reaction is energetically allowed.

Question 13.27:

Consider the fission of         by fast neutrons. In one fission event, no neutrons are

emitted and the final end products, after the beta decay of the primary fragments, are

and         . Calculate Q for this fission process. The relevant atomic and particle masses are

m             =238.05079 u

m              =139.90543 u

m             = 98.90594 u

Answer

In the fission of        , 10 β⁻ particles decay from the parent nucleus. The nuclear reaction can be written as:

It is given that:

Mass of a nucleus        m₁ = 238.05079 u Mass of a nucleus                                      m₂ = 139.90543 u Mass of a nucleus                                    , m₃ = 98.90594 u

Mass of a neutron       m₄ = 1.008665 u

Q-value of the above equation,

Where,

m’ = Represents the corresponding atomic masses of the nuclei

= m₁ − 92m_e

= m₂ − 58m_e

= m₃ − 44m_e

= m₄

Hence, the Q-value of the fission process is 231.007 MeV.

Question 13.28:

Consider the D−T reaction (deuterium−tritium fusion)

Calculate the energy released in MeV in this reaction from the data:

= 2.014102 u

= 3.016049 u

(b)Consider the radius of both deuterium and tritium to be approximately 2.0 fm. What is the kinetic energy needed to overcome the coulomb repulsion between the two nuclei? To what temperature must the gas be heated to initiate the reaction? (Hint: Kinetic energy required for one fusion event =average thermal kinetic energy available with the interacting particles = 2(3kT/2); k = Boltzman’s constant, T = absolute temperature.)

Answer

Take the D-T nuclear reaction:

It is given that:

Mass of      , m₁= 2.014102 u Mass of                        , m₂ = 3.016049 u Mass of                                     m₃ = 4.002603 u

Mass of     , m₄ = 1.008665 u

Q-value of the given D-T reaction is:

Q = [m₁ + m₂− m₃ − m₄] c²

= [2.014102 + 3.016049 − 4.002603 − 1.008665] c²

= [0.018883 c²] u

But 1 u = 931.5 MeV/c²

∴Q = 0.018883 × 931.5 = 17.59 MeV

Radius of deuterium and tritium, r ≈ 2.0 fm = 2 × 10⁻¹⁵ m

Distance between the two nuclei at the moment when they touch each other, d = r + r = 4

× 10⁻¹⁵ m

Charge on the deuterium nucleus = e

Charge on the tritium nucleus = e

Hence, the repulsive potential energy between the two nuclei is given as:

Where,

∈₀ = Permittivity of free space

Hence, 5.76 × 10⁻¹⁴ J or

of kinetic energy (KE) is needed to overcome the

Coulomb repulsion between the two nuclei.

However, it is given that:

KE

Where,

k = Boltzmann constant = 1.38 × 10⁻²³ m² kg s⁻² K⁻¹

T = Temperature required for triggering the reaction

Hence, the gas must be heated to a temperature of 1.39 × 10⁹ K to initiate the reaction.

Question 13.29:

Obtain the maximum kinetic energy of β-particles, and the radiation frequencies of γ

decays in the decay scheme shown in Fig. 13.6. You are given that

m (¹⁹⁸Au) = 197.968233 u

m (¹⁹⁸Hg) =197.966760 u

Answer

It can be observed from the given γ-decay diagram that γ₁ decays from the 1.088 MeV energy level to the 0 MeV energy level.

Hence, the energy corresponding to γ₁-decay is given as:

E₁ = 1.088 − 0 = 1.088 MeV

hν₁= 1.088 × 1.6 × 10⁻¹⁹ × 10⁶ J

Where,

h = Planck’s constant = 6.6 × 10⁻³⁴ Js

ν₁ = Frequency of radiation radiated by γ₁-decay

It can be observed from the given γ-decay diagram that γ₂ decays from the 0.412 MeV energy level to the 0 MeV energy level.