Explanation:
The activity of radioisotope is not affected by any external condition of temperature, pressure or chemical change.
Explanation:
Stellar and solar energy is due to fusion reactions. So, source of stellar energy is Nuclear fusion.
Explanation:
92V238 + n → 92A239
92A239 → 93B239+e
92B239 → 94C239+e
Finding the element C from periodic table
94Pu239
Explanation:
Isotope nucleus means that those nucleus has same protons number but different neutrons and mass number. Since chlorine has 17 protons so its isotope also will have 17 protons.
Explanation:
If an alpha particle is bombarded on a nitrogen (N-14) nucleus, an oxygen (O-17) nucleus and a proton are released.
According to the conservation of mass and charge,
$^4_2\text{He}+\text{ }^{14}_7\text{N}\rightarrow\text{ }^{17}_6\text{O}+\text{ }^1_1\text{p}$
So, the emitted particle is a proton.
Explanation:
One an amu is $\frac{1}{10}$ of the mass of one carbon-12 atom.
It is equal to $\frac{1}{\text{NA}}$
$\frac{1}{6.022\times10^{23}}$
= 1.66×10−24g.
Explanation:
Binding energy per nucleon in a nucleus first increases with increasing mass number (A) and reaches a maximum of 8.7MeV for A (50 - 80). Then, again it slowly starts decreasing with the increase in A and drops to the value of 7.5MeV.
Explanation:
Sir Einstein's mass-energy equation states that mass and energy can be converted into each other by the following relation.
E = mc2, (c = speed of light)
This implies that a small amount of mass contains a lot of energy, which can be proved with an example.
Let we have a mass of 1g = 10−3kg , therefore energy produced by it will be:
E = 10−3 × ( 3 × 108 ) 2 = 9 × 1013J
which is a vast amount energy produced by only one gram (small mass) of mass.
Whereas a small amount of energy doesn't give a large amount of mass because for that we have to divide the energy by c2, which gives a small mass.
Solution:
The moderator used have light nuclei like proton. When protons undergo perfectly elastic collision with the neutron emitted their velocities are exchanged, it means, neutrons come to rest and protons move with the velocity of neutrons.
Explanation:
When the train is stationary, the separation between the alpha particle and recoiling uranium nucleus is x in time t after the decay. Even if the decay is taking place in a moving train and the separation is measured by the passenger sitting in it, the separation between the alpha particle and nucleus will be x. This is because the observer is also moving with the same speed with which the alpha particle and recoiling nucleus are moving, i.e. they all are in the same frame that is moving at a uniform speed.
Explanation:
This is because in heavy nuclei, the $\frac{\text{N}}{\text{Z}}$ ratio becomes larger in order to maintain their stability and reduce instability caused due to the repulsion among the protons. The neutrons exert only attractive short-range nuclear forces on each other as well as on the neighbouring protons, whereas the protons exert attractive short-range nuclear forces on each other as well as the electrostatic repulsive force. Thus, the nuclei with high mass number, in order to be stable, have large neutron to proton ratio $\frac{\text{N}}{\text{Z}}.$
Explanation:
Radius of a nucleus with mass number A is given as
$\text{R}=\text{R}_{\text{0}}\text{A}^{\frac{1}{3}}$
Here, $\text{R}_0=1.2\text{fm}$
$\therefore$ Volume of the nucleus $=\frac{4\pi\text{R}^3}{3}=\frac{4\pi\text{R}^3\text{A}}{3}$
This depends on A. With an increase in A, V increases proportionally.
Mass of the nucleus $\simeq\text{Am}_{\text{N}}$
Here, mN is the mass of a nucleon.
Therefore, mass of the nucleus also increases with the increasing mass number. Binding energy also depends on mass number (number of nucleons) as it is the difference between the total mass of the constituent nucleons and the nucleus. Therefore, it also varies with the changing mass number.
On the other hand,
$\text{Density}=\frac{\text{Mass}}{\text{Volume}}$
$=\frac{\text{Am}_{\text{N}}}{\frac{4\pi\text{R}3}{3}}=\frac{\text{Am}_{\text{N}}}{\frac{4\pi\text{R}_0^3\text{A}}{3}}=\frac{\text{m}_{\text{N}}}{\frac{4\pi\text{R}_0^3}{3}}=\frac{3\text{m}_{\text{N}}}{4\pi\text{R}_{0}^3}$
This is independent of A and hence does not change as mass number increases.
Explanation:
In fast chain reaction neutron released in previous fission again strikes 235U, So size of 235U block should be greater than it's critical size.
Explanation:
Atomic mass of a compound is measured in atomic mass units abbreviated as amu or u. One atomic mass unit is defined as $\frac{1}{12}$th of mass of a single carbon-12 atom.
$\alpha-\text{decay}$
$\beta^+-\text{decay}$
Explanation:
In alpha particle decay, the unstable nucleus emits an alpha particle reducing its proton number (atomic number) Z as well as neutron number N by 2.
$\text{ }^{\text{A}}_{\text{Z}}\text{X}\rightarrow\text{ }^{\text{A}-4}_{\text{Z}-2}\text{Y}+\text{ }^4_2\text{He}$
During $\beta^--\text{decay},$ a neutron is converted to a proton, an electron and an antineutrino. Thus, there is an increase in the atomic number.
$\text{ }^{\text{A}}_{\text{Z}}\text{X}\rightarrow\text{ }^{\text{A}}_{\text{Z}+1}\text{Y}+\text{e}^-+\bar{\text{v}}$
During $\beta^+-\text{decay},$ a proton in the nucleus is converted to a neutron, a positron and a neutrino in order to maintain the stability of the nucleus. Thus, there is a decrease in the atomic number.
$\text{ }^{\text{A}}_{\text{Z}}\text{X}\rightarrow\text{ }^{\text{A}}_{\text{Z}-1}\text{Y}+\beta^++\text{v}$
When a nucleus is in higher excited state or has excess of energy, it comes to the lower state in order to become stable and release energy in the form of electromagnetic radiation called gamma ray. The element in the gamma decay doesn't change.
Therefore, alpha and beta plus decay suffer decrease in atomic number.
Explanation:
In nuclear physics, nuclear fusion is a nuclear reaction in which two or more atomic nuclei collide at a very high speed and join to form a new type of atomic nucleus. During this process, matter is not conserved because some of the matter of the fusing nuclei is converted to photons (energy).
Explanation:
$32\text{P}\\ \ 15$ is the radioactive isotope of phosphorous element.
As it has more number of neutrons than number of protons.
Explanation:
In a beta decay, either a neutron is converted to a proton or a proton is converted to a neutron such that the mass number does not change. Also, the number of the nucleons present in the nucleus remains the same. Thus, the active nucleus gets converted to one of its isobars after beta decay.
Explanation:
From the above figure it is clearly visible that the binding energy of the nucleus decreases on an average as A increases
Explanation:
For neutron decay, some mass disappears as neutrons convert to a proton, electron and antineutrino.
Q = (mn−mp−mνˉ−me)c2 = 0.782MeV
Explanation:
In endothermic reaction the binding energy of reactants is more than the binding energy of products.
Explanation:
Hydrogen is the lightest element in the universe with atomic number 1 and so, it has the simplest atomic structure.
Explanation:
The Sun produces energy by the nuclear fusion of hydrogen into helium in its core.
Explanation:
Alpha rays, beta-plus and beta-minus rays carry charged particles that show particle behaviour. On the other hand, gamma rays carry photons that show particle as well as wave behaviour. Hence, only gamma rays are electromagnetic waves.
Explanation:
A nucleus is made up of two fundamental particles-neutrons and protons. If a nucleus has more number of neutrons than what is needed to have stability, then neutrons decay into protons and if there's an excess of protons, then they decay to form neutrons. Since a neutron has larger rest mass than a proton, the Q-value of its decay reaction is positive and a free neutron decays to a proton, while an isolated proton cannot decay to a neutron as the Q-value of its decay reaction is negative. Hence, it is physically not possible.
Explanation:
James Chadwick discovered the neutron.
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11.
Atomic mass (u) of sodium = 23u.
It is a soft, silvery-white, highly reactive metal.
Explanation:
86Rn220 → 84Po216 + ZXA
Z + 84 = 86 and 220 = 216 + A
So, Z = 2 and A = 4
$2\alpha^4$
So, it is $\alpha$ particle.
Explanation:
Lithium atom contains 3 protons and 3 neutrons in the nucleus and 3 valence electrons. When two lithium nuclei are brought together, they repel each other. The attractive nuclear forces being short-range are insignificant as compared to the electrostatic repulsion. Thus, the nuclei do not combine to form carbon atom because of coulomb repulsion.
Explanation:
Isotopes of the same element must have same number of protons but different number of neutrons and hence they have different mass.
Also the isotopes of same element are not equally abundant in nature.
Explanation:
The average binding energy per nucleon is just the total binding energy divided by the number of nucleons. If we consider Na atom, its binding energy is 194MeV.
Its binding energy per nucleon is given by $\frac{194\text{MeV}}{24}$
= 8.08MeV
Solution:
Key Concept:
| Features | α- particles | β- particles | γ-rays | |
| 1. | Identity | Helium nucleus or doubly ionised helium atom (2He4) | Fast moving electron $(-\beta^0\text{ or }\beta^-)$ | Photons (E.M. waves) |
| 2. | Charge | +2e | -e | Zero |
| 3. | Mass | 4 mp (mp = mass of proton) = 1.87 × 10-27 | me | Massless |
| 4. | Equation of decay | $_\text{Z}\text{X}^\text{A} \xrightarrow{\alpha-\text{decay}}\ _{\text{z}-2}\text{Y}^{\text{A}-4}+_2\text{He}^4$ $\text{n}_\alpha=\frac{\text{A}-\text{A}'}{4}$ | $_\text{Z}\text{X}^\text{A}\rightarrow_{\text{z}-2}\text{Y}^{\text{A}}+_{-1}\text{e}^0+\overline{\text{v}}$ $_\text{Z}\text{Y}^\text{A}\xrightarrow{^\text{n}\beta}\ _{\text{z}'}\text{Y}^{\text{A}}$ $\Rightarrow\ \text{n}_\beta=(2\text{n}_\alpha-\text{Z}+\text{Z}')$ | $_\text{Z}\text{X}^\text{A}\rightarrow\ _\text{Z}\text{X}^\text{a}+\gamma$ |
A/3-particle carries one unit of negative charge (-e), an α-particle carries 2 units of positive charge (+2e ) and γ (particle) carries no charge. Hence electronic energy levels of the atom charges for α and β decay, but not for γ-decay.
Explanation:
The binding energy is a energy that holds the nucleus together.
Thus, more binding energy will give more stable nuclei. Here alpha particle has more binding energy so it will be more stable than deutron.
Explanation:
If the mass of fissionable material exceeds a critical value, chain reaction or self propagating fission reaction or self propagating fission reaction takes place.
Explanation:
We know that mass defect = combined mass of nucleons − mass of the nucleus.
Since mass defect is always positive quantity so the difference of nucleus and the combined mass of its nucleons will be negative. The combined mass is greater than the mass of nucleus.
Explanation:
$^{40}_{19}{\text{K}}$ is the radioactive isotope of Potassium element.
As it has more number of neutrons than number of protons.
Explanation:
Protons and neutrons are present inside the nucleus and they exert strong attractive nuclear forces on each other, which are equal in magnitude. Due to their positive charge, protons repel each other. Hence the net attractive force between two protons gets reduced, but the nuclear force is stronger than the electrostatic force at a separation of 1fm.
Explanation:
Isotopes of an element must have same atomic number (Z) but different mass number A.
Number of protons is equal to the atomic number.
So, isotopes of an element have same number of protons.
Mass number is equal to the sum of number of protons and neutrons i.e. A = p + n
As isotopes of an element have different mass number but same number of protons, thus they must have different number of neutrons.