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It is due to a concept taken from Newton's Law of Gravitation. It says that each mass element of the shell puts an attractive force on a particle inside but due to the fact that the shape of the shell is symmetrical, these forces cancel out in every direction.
To prove it mathematically, one can use Gauss's Law for Gravitation. It states that inside a uniformly distributed spherical shell, the net gravitational field is zero. It differs from electrostatics, which states that a conducting shell blocks or stops the external electric fields. The shielding concept is not part of gravitation where the external bodies exert a gravitational force on an object inside the shell. It is the fundamental property of astrophysics and helps in understanding why the gravitational field inside a star or planet depends only on the mass enclosed within a given radius.

Gravitational Potential Energy (U) is the energy an object has due to its position in a gravitational field. It is defined as:

Where M represents the mass of the larger body, m is the mass of the smaller body, r is the distance between them, and G stands for the gravitational constant.
G is written with a negative sign to show that the gravitational potential energy is always lower than zero and the values even decrease as the objects move apart from each other. It implies that to separate two masses, work should be done against the gravity. At infinity, U = 0, implying that no external force is required to keep them apart. When two objects are closer, potential energy is more negative which implies a stronger gravitational attraction. The concept is very important in fields such as orbital mechanics and astrophysics.

According to Newton's Law of Universal Gravitation, each object in the universe attracts every other object with a force that depends on the distance between them and their masses. This force is mathematically given by the following formula:

Here, F is the gravitational force, G is the gravitational constant and m? and m? refers to the masses of the objects, and r represents the distance between them.

Newton's Law of Universal Gravitation explains the behaviour of tides due to the Moon's gravity, planetary motion, and even how satellites orbit the Earth. This law is widely used in space research and astrophysics to find out the masses of the celestial bodies and how they interact with each other. It is accurate in most cases but for extreme gravitational fields, instead of Newton's law, Einstein's General Theory of Relativity is more useful.

NCERT Class 12 Chemistry Chapter 7 Alcohols, Phenols, and Ethers, is highly significant for JEE Mains as it forms a fundamental part of organic chemistry.  Chapter 7 Alcohol, Phenol, and Ethers is frequently asked in JEE Mains with 1-2 direct questions every year. Questions are asked aften in the form of Conversions & Reaction Mechanisms,  Acidity and Basicity Comparisons, and Named Reactions. NCERT Solutions for Class 12 Chemistry Ch 7 can be very helpful resource, Studenst can use that for practicing, revision, and conceptual understanding. Students can check solutions link below;

NCERT Solutions For Class 12 Chemistry Chapter 7 Alcohols, Phenols, and Ethers

Students who wish to study offline can download the NCERT Class 12 Physics Chapter 12 Atoms PDF from Shiksha's homepage or other educational platforms. This allows students to access NCERT Solutions PDFs anytime without an internet connection. 

NCERT Solution Class 12 Physics Ch 12 Atoms PDF: Download Free PDF

The PDF provides a detailed explanations along with solved numerical problems, and conceptual insights to help students revise and prepare better. By downloading the PDF, students can practice various types of theoretical and numerical questions, which improve their problem-solving skills and boosts their exam performance.

Class 12 Physics Ch 12 Atoms NCERT Solutions covers various important topics that play a significant role in modern physics. Here are some of the topics students must include during their exam preparation:

• Rutherford's Atomic Model

• Bohr's Model of the Hydrogen Atom

• Energy Quantization

• The Hydrogen Spectral Series (Lyman, Balmer, Paschen, Brackett, and Pfund series)

• de Broglie's Explanation of Bohr's Second Postulate

• The Limitations of Bohr's Model. 

Additionally, it also includes X-ray Spectra and Moseley's Law, which help explain the relationship between atomic number and X-ray frequency. These concepts are frequently asked in board exams and entrance exams like JEE and NEET.

NCERT Solutions for Class 12 Physics Chapter 12 Atoms are important for students preparing for CBSE board exams as well as competitive exams like JEE and NEET. 

Class 12 Physics Chapter 12 Atoms conisists of fundamental concepts such as Hydrogen Spectral Series, Rutherford's Atomic Theory, Bohr's Model, and Energy Quantization. Being aware of these concepts will prepare students build a strong foundation in modern physics, which is important for advanced studies in engineering and medical fields. The NCERT solutions pdfs also provide step-by-step problem-solving methods, making it easier for students to tackle with numerical and theoretical questions in a much better way.