50 questions · timed · auto-graded
Explanation:
$\beta^-$ emission is due to decay of neutron in the nucleus n → p + e−.
Explanation:
Fusion reaction takes place at temperature about 107K.
It requires this high temperature so that nucleus are moving rapidly, so that they have high kinetic energy and can come together by overcoming repulsion between them.
Statement-II: For heavy nuclei, binding energy per nucleon increases with increasing Z. while for light nuclei it decreases with increasing Z.
Explanation:
Statement-I: Both, heavy nuclei and light nuclei have low value of binding energy per nucleon. Heavy nuclei splits (fission) into light nuclei and light nuclei combine (fusion) to attain the stability i.e. higher value of binding energy per nucleon. In both processes, some mass is disappeared which is converted into energy i.e. release of energy. (statement is TRUE).
Statement-II: For heavy nuclei the binding energy decreases with increasing Z and for light nuclei binding energy per nucleon increases with increasing Z.
Explanation:
The nucleus of each atom contains protons and neutrons. While the number of proton defines the element and the number of neutrons defines the isotope of the element. Radioactive isotopes are unstable and decays into other elements.
Explanation:
Before Sir Einstien, mass and energy were two completely different physical quantities, which were not related to each other anyway.
Sir Einstein told that energy and mass are related to each other i.e. energy and mass can be converted into each other by the following relation:
E=mc2, called Sir Einstein's mass-energy equivalence.
Solution:
Key coneept:
Nuclear Fusion: In nuclear fusion two or more than two lighter nuclei combine to form a single heavy nucleus. The mass of a single nucleus so formed is less than the sum of the masses of parent nuclei. This difference in mass results in the release of tremendous amount of energy To achieve fusion, you need to create special conditions to overcome this tendency.
Here are the conditions that make fusion possible:
High Temperature: The high temperature gives the hydrogen atoms enough energy to overcome the electrical repulsion between the protons.
High pressure: Pressure squeezes the hydrogen atoms together. They must be within 1 × 10-15 metres of each other to fuse.
Fusion processes are impossible at ordinary temperatures and pressures. The reason is that nuclei are positively charged and nuclear forces are short range strongest forces. In order to force two hydrogen nuclei together, we need to have a very high pressure, or a very high temperature, or both. A high pressure helps because it causes all the hydrogen nuclei in the sun to squeeze into a smaller space. Then there is more chance of one hydrogen bumping into another. A high temperature helps because it makes the hydrogen nuclei move faster. They need this extra speed so that they can get close together and join. It is as if the nucleus has to break through a barrier, and so the faster it is moving, the greater chance it has.
So, at the "normal" temperature and pressure on earth, a hydrogen nucleus has basically no chance of ever joining with another hydrogen nucleus.
Important point: We know that in the middle of the sun, where the temperature is about 16 million degrees, and the pressure is 250 billion atmospheres, hydrogen nuclei will sometimes have enough energy to join together. (An atmosphere is the "normal", pressure of the air here on earth. A pressure of 250 billion atmospheres is like having a large mountain piled on top of you!)
Explanation:
The fission bomb or atom bomb works on the principle that it takes energy to put together a nucleus with many protons and neutrons.
Explanation:
Stability of nucleus is based on average binding energy i.e. binding energy per nucleon. This much energy will be needed for nucleon to break free.
Explanation:
Extremely high temps needed for fusion because K.E. should large enough to overcome repulsion between nuclei.
Explanation:
When two or smaller nuclei combine to form a bigger nucleus, then the reaction is known as nuclear fusion reaction. A huge amount of energy is released in such reactions.
Explanation:
Atomic weight is specific for a particular element and does not change under any circumstances.
Explanation:
An α particle has two protons and two neutrons and zero electrons. It is written as $^4_2\text{He}^{2+}$.
So if it captures an electron, the reaction is:
$^4_2\text{He}^{2+}$ + +e− → $^4_2\text{He}^{+}$
Explanation:
The nuclear reaction: 15P30 → 4Si30+ +1e0
Thus a positron is emitted during the decay of 15P30 into 14Si30.
Explanation:
The maximum binding energy per nucleon occurs at around mass number A = 50, and corresponds to the most stable nuclei. Iron nucleus F56 is located close to the peak with a binding energy per nucleon value of approximately 8.8MeV . It’s one of the most stable nuclides that exist.
Explanation:
Isotopes are atoms with the same number of protons but that have a different number of neutrons.
Since the atomic number is equal to the number of protons and the atomic mass is the sum of protons and neutrons, we can also say that isotopes are elements with the same atomic number but different mass numbers.
Explanation:
Mass defect = mass of nucleons - mass of nucleus
= (3 × 1.007277 + 4t008665) − 7.016005
= 0.040486amu
$≈$ 0.04050
Explanation:
Fusion reactions takes place at temperature about 107K it requires this high temperature so that nucleus are moving at very high speed, so that they have high kinetic energy and can overcome the repulsion between nuclei and come together.
Explanation:
22Ne decays
$\alpha$particle = He2+
Mass No = 4
p = 2, n = 2
So, New mass no. = 22 − 8 = 14
Atomic No. = 10 − 4 = 6
So, the new element is 6C14
Explanation:
Binding energy per nucleon increases with atomic number. The greater the binding energy per nucleon the more stable is the nucleus.
For 26Fe56 number of nucleons is 56.
This is most stable nucleus, since maximum energy is needed to pull a nucleon away from it.
Explanation:
In exothermic reaction the binding energy of reactants is less than the binding energy of products.
Explanation:
Fusion reaction takes place at temperatures around 107k. It requires this high temperature so that nucleus start moving at rapidly speed, which in turn increases their kinetic, so that they overcome the repulsion between them and can come together.
Explanation:
Hydrogen has 3 isotopes namely. protium $1\text{H}\\1$, deuterium $2\text{H}\\1$ and tritium $3\text{H}\\1$
Explanation:
57Co is undergoing beta decay, i.e. electron is being produced. But an electron has very less mass (9.11 × 10-31kg) as compared to the Co atom. Therefore, after 570 days, even though the atoms undergo large beta decay, the weight of the material in the container will be nearly 10g.
Explanation:
The half-life of a radioactive sample $\Big(\text{t}_{\frac{1}2{}}\Big)$ is defined as the time elapsed before half the active nuclei decays.
Let the initial number of the active nuclei present in the sample be N0.
$\frac{\text{N}_{0}}{2}=\text{N}_{\text{0}}\text{e}^{-\lambda\text{t}_{\frac{1}2{}}}$
$\Rightarrow\text{t}_{\frac{1}{2}}=\frac{\text{In}2}{\lambda}$
Average life of the nuclei, $\text{t}_{\text{av}}=\frac{\text{S}}{\text{N}_{0}}=\frac{1}{\lambda}$
Here, S is the sum of all the lives of all the N nuclei that were active at t = 0 and $\lambda$ is the decay constant of the sample.
Explanation:
The process of splitting a nucleus is called nuclear fission. Uranium or plutonium isotopes are normally used as the fuel in nuclear reactors, because their atoms have relatively large nuclei that are easy to split, especially when hit by neutrons.
When fission of an element takes place when hit by a neutron, further more neutrons are released. The additional neutrons released may also hit other uranium or plutonium nuclei and cause them to split. Even more neutrons are then released, which in turn can split more nuclei. This is called a chain reaction.
Explanation:
Isotopes of the same element must have same number of protons but different number of neutrons.
Also the isotopes of same element are located at same place in the periodic table and undergo same chemical reaction.
Explanation:
From conservation of energy:
Change in energy = Energy of reactants − Energy of products − Q>0 (Endothermic)
Therefore, minimum energy of reactants >Q=11.32 MeV
Explanation:
Nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons and/or protons).
The difference in mass between the products and reactants is manifested as the release of large amounts of energy.
A hydrogen bomb derives its energy from this type of nuclear reaction.
Explanation:
Because thermal energy decreases, therefore mass should increase.
Solution:
Given, $\text{F}=\frac{\text{GMm}}{\text{r}^2}$
M = Effective mass of hydrogen atom = mass of electron + mass of proton - $\frac{\text{B}^2}{\text{C}}$
Where B is BE of hydrogen atom = 13.6eV.
Solution:
The two samples of the Two radioactive nuclides A and B can simultaneously have the same decay rate at any time if initial rate of decay of A is twice the initial fate of decay of B and $\lambda_\text{A}>\lambda_\text{B}$. Also, when initial rate of decay of B is same as rate of decay of A at t = 2h and $\lambda_\text{B}>\lambda_\text{A}$.
Explanation:
Binding energy per nucleon = 5.6MeV
No. of nucleon = No. of proton + No. of neutron
= 3 + 4 = 7
So, for 7 Nucleon = 7 × 5.6 = 39.2MeV
Explanation:
In nuclear physics, a unit used for measurement of mass is unified atomic mass unit, which is denoted by u.
It is defined such that
$1\text{u}=\frac{1}{12}\times$ (Mass of neutral carbon atom in its ground state)
Mass of neutral carbon atom in its ground state = 12 × 1u = 12u
Thus, the mass of neutral carbon atom in its ground state is exactly 12u.
Explanation:
Ionic bonding is the electrostatic force of attraction between positively and negatively charged ions. The ions have been produced as a result of transfer of electrons between two atoms with a large difference in electronegativity.
As the ionic bond is a strong bond high energy is required to break the bond. Hence high temperature is needed to indicate the nucleus fusion reaction.