Nuclei

Nuclei

Edited By Team Careers360 | Updated on May 06, 2022 10:58 AM IST

Introduction:
The atomic nucleus is the tiny, dense area of protons and neutrons at the heart of an atom. A positively-charged atom is composed of an atom that is surrounded by a cloud of negatively-charged electrons that are held together by electrostatic force. We've noticed that practically all of an atom's mass is concentrated in the nucleus. The electron cloud is thought to have just a little role to play in this. The nuclear force binds protons and neutrons together to create a nucleus. The residual strong force (nuclear force) binds nuclei together. The residual strong force, which binds quarks together to create protons and neutrons, is a tiny remnant of the strong interaction. We've known the phrase "force" since we were children. In the most basic terms, it is defined as any push or pull that may be described in general terms. The nuclear force is strongly attractive at normal nucleon separation distances, and the electromagnetic force overcomes the repulsion between protons, allowing nuclei to exist. However, because it decays swiftly with distance, it has a limited range, and only nuclei smaller than a specific size may be totally stable. A significant amount of active research is focused on nuclei with up to eight nucleons in order to evaluate various characteristics of light. These are the simplest of all nuclei, and the first quantitative comparisons of their global and short-range organisation have been made between experimental and theoretical maps. These nuclei, especially those associated with gluons and quarks, are suitable for studying the microscopic elements of nuclear structure. Light nuclei have a vital role in astrophysics, elementary particle physics, and energy generation.

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List of topics according to NCERT and JEE Main/NEET syllabus:

Composition of Nucleus
Nuclear Density
Radioactivity
Radioactive Decay
Radioactivity Decay Law
Half-life
Decay Constant
α- Decay
β-Decay
γ-Decay

Related Topics,

Important concepts and Laws:

Radioactivity is the spontaneous breakdown of an atom's nucleus, which results in the emission of one or more radiations such as alpha, beta and gamma radiations.

Radioactive Decay is a nuclear transformation process in which radioactive rays are released from an atom's nucleus. Any physical or chemical action cannot speed up or slow down this process.

The Law of Radioactivity Decay - The rate of decay of radioactive atoms is proportional to the number of atoms present at any given time, according to this rule.

The half-life of a radioactive element is defined as the amount of time it takes for half of the number of atoms present in the sample to decay.

The average life of a radioactive element may be calculated by dividing the entire life period of all the atoms in the radioactive element by the total number of atoms present in the sample of the element at the start.

The radioactive decay constant is defined as the reciprocal of the time it takes for the number of atoms in a radioactive substance to fall to 36.8% of their original number.

Radioactive Displacement Law - Also known as Fajans and Soddy law, the law of radioactive displacement governs the movement of radioactive matter. This law specifies which chemical elements and isotopes are produced during a certain kind of radioactive decay.

- Decomposition In alpha decay, the product nucleus has a mass number four less than that of the decaying nucleus, but the atomic number reduces by two.

β-Decay The mass number of the product nucleus does not change in -decay, but the atomic number does rise or drop by one.

An electron and an antineutrino are generated and ejected from the nucleus in beta-minus decay (–).

A positron and a neutrino are produced and ejected from the nucleus in beta-plus decay (+).

γ-Decay When an or -decay occurs in an excited daughter nucleus, a -ray is released. Atoms then return to their ground state by a single photon transfer or a series of photon transitions.

NCERT Notes Subject wise link:

Importance of nuclei for class 12

Nuclei is an important chapter as there is a trend in the exams like jee mains and NEET of asking the same type of question and from the same topics these topics are half life and radioactivity . nuclei are connected with the chapter 12 atom as they combine to form the unit . As a result, nuclei is a prominent topic in board exams, as well as a critical component of the joint entrance exam (jee), national entrance test, and National Eligibility Cum Entrance Test (neet). Students must be thorough in their study in order to do well in the category 12 board exam. Students must plan ahead of time and practise.

NCERT Solutions Subject wise link:

NCERT Exemplar Solutions Subject wise link:

Frequently Asked Questions (FAQs)

1. What is the definition of a nucleus?

It is characterised as a collection of positively charged protons and electrically neutral neutrons. Quarks are the particles that makeup neutrons and protons.

2. What are the topics taught in Nuclear Physics?

Nuclear weapons, nuclear power, medicine, magnetic imaging resonance, ions implantation, engineering, cultural and industrial isotopes, radiocarbon dating in geology, and nuclear engineering are some of the themes covered.

3. Why are there always more protons than neutrons in stable nuclei?

Protons are positively charged sections of the atom, which means they oppose each other electrically. When there are more than 10 protons in a nucleus, this repulsion becomes excessive. As a result, a higher number of neutrons, which create only attractive forces, is required for stability.

4. Is it possible to conclude that electrons exist inside the nucleus based on beta decay?

No, despite being an electron, the beta particle is generated and expelled at the same time as beta decay. It will be unable to exist within the nucleus due to the de-Broglie wavelength, which is far bigger than the nucleus' size.

5. The total mass of a nucleus' components – neutrons and protons – is always smaller than the mass of the nucleus in its ground state. Explain.

When nucleons come together to form a nucleus, they are strongly attracted to one another. Their potential energy is dwindling and turning negative. The nucleons in the nucleus are held together by this potential energy. As the potential energy of the nucleon decreases, the mass of the nucleon inside the nucleus decreases as well.