Anand Classes explains the Van der Waals radius is a measure of the size of an atom when it is not bonded to another atom but held together by weak Van der Waals forces in the solid state. Unlike covalent radius, which is measured for bonded atoms, Van der Waals radius is determined for non-bonded atoms in neighbouring molecules. This concept is especially important for noble gases, which do not form covalent bonds and therefore have their atomic radii expressed in terms of Van der Waals radii.

Anand Classes explains the atomic radius of elements shows a clear trend when we move down a group in the periodic table. For both alkali metals (Group 1) and halogens (Group 17), the atomic radius increases as we go from top to bottom. This happens because each successive element down the group has an additional electron shell in its electronic configuration. The added shell increases the distance between the outermost electrons and the nucleus, while the shielding effect of inner electrons reduces the effective nuclear pull. As a result, the atoms become larger despite the increasing nuclear charge.

Anand Classes Notes explains across any period in the periodic table, atomic radius generally decreases from left to right. This trend occurs because as the atomic number increases, the nuclear charge grows while electrons are added to the same principal energy level. Without significant shielding from electrons in the same shell, the increased effective nuclear pull draws electrons closer to the nucleus, resulting in a smaller atomic size.

Anand Classes Notes explains in atoms with more than one electron, the outer electrons are repelled by the inner electrons due to electron–electron repulsion. This repulsion reduces the full attractive force of the positively charged nucleus on the valence electrons. This phenomenon is known as the screening effect or shielding effect. The greater the number of inner electrons, the larger the shielding effect, which decreases the effective nuclear charge (Zeff) experienced by the outermost electrons. Slater, a scientist, formulated rules to calculate this shielding effect quantitatively, which are essential for understanding atomic structure and periodic trends.

Anand Classes Notes explains Atomic radius refers to the distance from an atom’s nucleus to its outermost electron shell, measured in different ways depending on context—covalent radius, metallic radius, or van der Waals radius. Understanding these radius types and their trends is vital for solving Class 11, NEET, and JEE chemistry problems on periodic properties and atomic structure.

Anand Classes explains the periodic table is not just a list of elements—it’s a powerful tool that reveals the underlying pattern in chemical behavior. This repeating pattern, known as periodicity, occurs because elements with similar valence shell electron configurations exhibit similar chemical and physical properties. As we move across periods or down groups, these patterns repeat at regular intervals due to the systematic arrangement of electrons, especially in the outermost shell. Understanding this cause of periodicity helps explain why elements in the same group behave alike in reactions and form similar compounds.

Anand Classes Notes explain the arrangement of elements in the periodic table follows a specific order based on the filling of electrons in atomic orbitals. From the fourth period onward, the pattern becomes more complex due to the involvement of d- and f-block orbitals. These periods include not only s- and p-block elements but also transition and inner transition elements. Understanding how these orbitals are filled explains why some periods have 18 or even 32 elements, unlike the shorter first three periods.

Anand Classes explain in the periodic table, elements are arranged in periods (horizontal rows) based on the way their electrons fill up different energy levels (shells). Each period starts with the filling of a new energy shell, and the number of elements in a period depends on how many orbitals are available in that shell to hold electrons. Let’s explore the electronic configurations of elements in the first three periods and understand why each period has a specific number of elements.

Anand Classes explain how To find the position of an element in the periodic table, we can use its electronic configuration. This helps us easily determine the period, group, and block to which the element belongs. In this post, we’ll go through simple solved examples to understand how to apply these rules step by step. This is very helpful for students preparing for JEE, NEET, and CBSE Class 11 exams.

Anand Classs Notes explain In Chemistry we can easily find the period, group, and block of an element in the periodic table by looking at its electronic configuration. This means, by knowing how the electrons are arranged in an atom, we can tell where the element is placed in the periodic table. It helps us understand the element’s properties and how it reacts with other elements.

Anand Classes explains the number of elements in each period of the periodic table follows the pattern 2, 8, 8, 18, 18, 32, 32 due to the way electrons fill atomic orbitals according to the Aufbau principle and the (n + l) rule. Each period corresponds to the filling of a new principal energy level, and the number of elements in that period depends on the total electron capacity of the subshells being filled. Understanding this explains why the 1st period has only 2 elements, the 2nd and 3rd periods have 8 elements each, the 4th and 5th periods have 18, and the 6th and 7th periods have 32 elements — an important concept for Class 11 Chemistry, JEE, and NEET.

The period and group number of an element in the periodic table can be determined from its electronic configuration using specific rules for s-, p-, d-, and f-block elements. These rules depend on the principal quantum number (n), the distribution of electrons in the outermost orbitals, and the block to which the element belongs. Knowing these rules is essential for solving periodic table questions in Class 11 Chemistry, JEE, and NEET.

Anand Classes Notes of Metals, non-metals, and metalloids are distributed in the periodic table according to their electronic configuration and chemical properties. Metals occupy the left and central portions of the table, non-metals are located on the right side, and metalloids lie along the zig-zag line separating the two. Understanding their position helps explain periodic trends such as metallic and non-metallic character, reactivity, and the types of oxides they form — an important topic in Class 11 Chemistry, JEE, and NEET.

The periodic table is divided into four main blocks — s-block, p-block, d-block, and f-block elements — based on the type of orbital that receives the last electron. Each block has unique position, electronic configuration, properties, and examples, making their comparison important for Class 11 Chemistry, JEE, and NEET preparation. This comparison covers their position in the periodic table, oxidation states, reactivity, metallic character, and special properties in a clear tabular format along with FAQs for quick revision.

Anand Classes Notes of f-Block elements, also called inner-transition elements, are located separately at the bottom of the periodic table. In these elements, the f-subshell of the inner-penultimate shell ((n-2)f shell) is progressively filled while the outermost shells have similar configurations. These elements show unique physical and chemical properties and are important for JEE, NEET, and CBSE Class 11 Chemistry.

Anand Classes Notes of d-Block elements, also known as transition elements, are located in Groups 3 to 12 of the …

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Anand Classes Class 11 Notes of Elements with atomic numbers greater than 100 are synthetic, man-made superheavy elements that do not occur naturally and are produced in laboratories or nuclear reactors. Since their discovery often led to naming disputes, the International Union of Pure and Applied Chemistry (IUPAC) introduced a systematic nomenclature based on the digits of the atomic number. According to this system, each digit is replaced with a specific prefix and the name ends with “-ium”, ensuring unique temporary names and symbols until permanent names are officially assigned.

Anand Classes notes of p-Block elements in the modern periodic table consist of Groups 13 to 18, and they include some of the most important families such as the boron family, carbon family, nitrogen family, oxygen family (chalcogens), halogens, and noble gases. Their general electronic configuration is ns²np¹–⁶, which gives them a wide range of properties from highly reactive non-metals (like halogens) to completely inert noble gases. The p-Block contains a unique combination of metals, non-metals, and metalloids, and it plays a crucial role in Class 11 chemistry, JEE, and NEET exam preparation.

ANAND CLASSES notes of s-block elements of the periodic table include all elements whose last electron enters the s-orbital. These elements, which consist of alkali metals (Group 1) and alkaline earth metals (Group 2), are highly significant in inorganic chemistry because of their reactivity, periodic trends, and wide applications in daily life. This article is authored by Neeraj Anand and published by Anand Technical Publishers to provide clear and exam-oriented explanations for JEE and NEET students, following the NCERT Class 11 Chemistry syllabus.

Anand Classes presents a comprehensive explanation of the Modern Periodic Table, authored by Neeraj Anand and published by Anand Technical Publishers. This detailed guide is tailored for students preparing for JEE, NEET, and Class 11 CBSE Chemistry, covering the fundamental concepts of the Modern Periodic Law, the structure of the periodic table, and the classification of elements into periods, groups, and blocks. With a focus on clarity, exam relevance, and NCERT alignment, this article serves as an essential resource for mastering one of the most important topics in inorganic chemistry.