###### Advertisements

###### Advertisements

A nucleus with mass number A = 240 and BE/A = 7.6 MeV breaks into two fragments, each of A = 120 with BE/A = 8.5 MeV. Calculate the released energy.

###### Advertisements

#### Solution

The binding energy of the nucleus of mass number 240, B_{1}=7.6×240=1824 MeV

The binding energy of each product nucleus, B_{2}=8.5×120=1020 MeV

Then, the energy released as the nuclues breaks is given by

E=2B_{2}−B_{1}=2×1020−1824=216 MeV

#### RELATED QUESTIONS

In the study of Geiger-Marsdon experiment on scattering of α particles by a thin foil of gold, draw the trajectory of α-particles in the coulomb field of target nucleus. Explain briefly how one gets the information on the size of the nucleus from this study.

From the relation *R* = *R*_{0} *A*^{1}^{/3}, where *R*_{0} is constant and *A* is the mass number of the nucleus, show that nuclear matter density is independent of *A*

Two stable isotopes of lithium `""_3^6"Li"` and `""_3^7"Li"` 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, `""_5^10"B"` and `""_5^11"B"`. 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 `""_5^10"B"` and `""_5^11"B"`.

Find the Q-value and the kinetic energy of the emitted α-particle in the α-decay of `""_88^226 "Ra"`.

Given `"m"(""_88^226"Ra")` = 226.02540 u, `"m"(""_86^222 "Rn")` = 222.01750 u,

`"m"(""_86^220 "Rn")`= 220.01137 u, `"m"(""_84^216 "Po")`= 216.00189 u.

The nucleus `""_10^23"Ne"` decays by `beta^(-)`emission. Write down the β decay equation and determine the maximum kinetic energy of the electrons emitted. Given that:

`"m"(""_10^23 "Ne")` = 22.994466 u

`"m"(""_11^23 "Na")` = 22.989770 u.

What do you mean by polar molecules and non-polar molecules? Give ‘one’ example each.

Name a material which is used in making control rods in a nuclear reactor.

Write one balanced equation to show Emission of `beta^-` (i.e. a negative beta particle)

With the help of a suitable example and an equation, explain the term pair production.

Two nuclei have mass numbers in the ratio 1: 2. What is the ratio of their nuclear densities?

If neutrons exert only attractive force, why don't we have a nucleus containing neutrons alone?

The mass number of a nucleus is

Potassium-40 can decay in three modes. It can decay by β^{−}-emission, B*-emission of electron capture. (a) Write the equations showing the end products. (b) Find the *Q*-values in each of the three cases. Atomic masses of `""_18^40Ar` , `""_19^40K` and `""_20^40Ca` are 39.9624 u, 39.9640 u and 39.9626 u respectively.

(Use Mass of proton m_{p} = 1.007276 u, Mass of `""_1^1"H"` atom = 1.007825 u, Mass of neutron m_{n} = 1.008665 u, Mass of electron = 0.0005486 u ≈ 511 keV/c^{2},1 u = 931 MeV/c^{2}.)

The atomic mass of Uranium `""_92^238"U"` is 238.0508 u, while that of Thorium `""_90^234"Th"` is 234.0436u, and that of Helium `""_2^4"He"` "is 4.0026u. Alpha decay converts `""_92^238"U"` into `""_92^234"Th"` as, shown below:

`""_92^238"U" -> ( ""_90^234"Th" + ""_2^4"He" + "Energy" )`

What is a neutrino?

\[\ce{^197_79Au}\] contains ______.

All nuclides with same mass number A are called ______.

A vessel contains oil (density 0.8 g/cm^{3}) over mercury (density 13.6 g/cm^{3}). A sphere of homogeneous composition floats with half its volume immersed in mercury and the other half in oil. The density of the material of the sphere in g/cm^{3} is ______.

A nucleus _{y}Y^{x} emits one α and two β particles. The resulting nucleus is ______.

Two cars of mass m_{1} and m_{2} are moving in circles of radii r_{1} and r_{2}, respectively. Their speeds are such that they make complete circles at the same time t. The ratio of their centripetal acceleration is:

The valance electrons in alkali metal is a:-

The mass number of a nucleus is equal to the number of:-

Deuteron is a bound state of a neutron and a proton with a binding energy B = 2.2 MeV. A γ-ray of energy E is aimed at a deuteron nucleus to try to break it into a (neutron + proton) such that the n and p move in the direction of the incident γ-ray. If E = B, show that this cannot happen. Hence calculate how much bigger than B must E be for such a process to happen.

Before the neutrino hypothesis, the beta decay process was throught to be the transition, `n -> p + vece`. If this was true, show that if the neutron was at rest, the proton and electron would emerge with fixed energies and calculate them. Experimentally, the electron energy was found to have a large range.

James Chadwick, in 1932 studied the emission of neutral radiations when Beryllium nuclei were bombarded with alpha particles. He concluded that emitted radiations were neutrons and not photons. Explain.

Mass numbers of two nuclei are in the ratio of 4 : 3. Their nuclear densities will be in the ratio of ______.

Which of the following are the constituents of the nucleus?

What conclusion is drawn from Rutherford’s scattering experiment of α-particles?