MCQ 11 Mark
Two nuclei have their mass numbers in the ratio of 1:27. The ratio of their nuclear densities are-
- A$1: 27$
- ✓$1: 1$
- C$1: 3$
- D$1: 9$
Answer
View full question & answer→Correct option: B.
$1: 1$
B
50 questions · timed · auto-graded
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 endothermic reaction the binding energy of reactants is more than the binding energy of products.
Explanation:
Mass defect is the amount by which the mass of an atomic nucleus differs from the sum of the masses of the consistuent particles, being the mass equivalent of the energy released in the formation of the nucleus. It is also the measure of binding energy of the nucleus.
Explanation:
Mass number of a nucleus is defined as the sum of the number of neutron and protons present in the nucleus, i.e. the number of nucleons in the nucleus.
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 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 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:
When an atom undergoes $\beta$-decay the atomic number increases by 1.
When an atom undergoes $\beta$-decay, one of the neutrons breaks into one proton and one electron. The resultant electron is then ejected out of the nucleus and this is called as the $\beta$ particle.
While the resultant proton stays inside the nucleus which results in increase of atomic number by 1, whereas the atomic mass remains invariant.
Explanation:
Hydrogen bomb is based on nuclear fusion. A large amount of nuclear energy is released by fusion of two light elements (elements with low atomic numbers).
In a hydrogen bomb, two isotopes of hydrogen, deuterium(1 proton, 1 neutron) and tritium(1 proton, 2 neutron) are fused to form a nucleus of helium and a neutron.
This fusion releases 17.6 MeV of energy. Also, there is no limit on the amount of the fusion that can occur.
Explanation:
In exothermic reaction the binding energy of reactants is less than the binding energy of products.
Explanation:
12C and 14C are the two isotopes of carbon atom that have same atomic number, but different mass numbers. This means that they have same number of protons and electrons, but different number of neutrons. Therefore, 12C has 6 protons, 6 electrons and 6 neutrons, whereas 14C has 6 electrons, 6 protons and 8 neutrons.
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:
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:
The concept of atomic mass was proposed by William Prout. Early atomic mass theory was proposed by the English chemist William Prout in a series of published papers in 1815 and 1816. Known as Prout's Law, Prout suggested that the known elements had atomic weights that were whole number multiples of the atomic mass of hydrogen.
Explanation:
Nuclear fusion reactions are the nuclear reactions in which two or smaller (lighter) nuclei combine to form a bigger (heavier) nucleus giving off a huge amount of energy.
Explanation:
Atomic mass (u) of Calcium is 40 u.
Explanation:
Alpha particle has highest mass of the given option which is he rest mass of the alpha particle amounts to 6.64424 × 10−27kg.
Mass of neutron is 1.0086654 a.m.u.
Mass of electrons = 9.10938291 × 10−31 kilograms.
Hence mass of alpha particle is greatest.
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:
The atomic weight is a characteristic property of an element and can never vary.
The valency of an element can vary. For example, when the ion is in +2 and +3 oxidation state, its valency is 2 and 3 respectively.
Explanation:
Radioactive isotopes have unstable nucleus which emits energy and particles when it converts to stable form. Cobalt-60 is an isotope used to treat Cancer like problems.
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.
Explanation:
A freshly prepared radioactive source emits radiation of intensity that is 64 times the permissible level. This means that it is possible to work safely till 6 half-lives (as 26 = 64) of the radioactive source. Since the half-life of the source is 2h, the minimum time after which it would be possible to work safely with this source is 12h.
Explanation:
The minimum amount of fissile material needed to maintain a nuclear chain reaction.
Explanation:
Extremely high temps needed for fusion because K.E. should large enough to overcome repulsion between nuclei.
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:
Radiocarbon is produced in the atmosphere as result of collision between fast neutrons and nitrogen nuclei present in the atmosphere.
Nuclear reaction is given as:
7N14 + 0n1 → 6C14 + 1H1
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:
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.
Explanaiton:
2A → B
Possible if B is more stable than A
⟹ Energy of B is less than two atoms of A
E2<2E1
Explanation:
Fusion reaction takes place at 107k
So, the correct choice is 3×106K
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:
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:
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:
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