{"id":4010,"date":"2026-03-30T08:01:04","date_gmt":"2026-03-30T08:01:04","guid":{"rendered":"https:\/\/ksquareinstitute.in\/blog\/?p=4010"},"modified":"2026-04-03T12:30:56","modified_gmt":"2026-04-03T12:30:56","slug":"structure-of-atom-class-11","status":"publish","type":"post","link":"https:\/\/ksquareinstitute.in\/blog\/structure-of-atom-class-11\/","title":{"rendered":"Structure of Atom Class 11: NEET Notes, Formulas, and Important Concepts"},"content":{"rendered":"\n<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n    <meta charset=\"UTF-8\">\n    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n    <link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n    <link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\n    <link href=\"https:\/\/fonts.googleapis.com\/css2?family=DM+Sans:wght@300;400;500;600&#038;family=JetBrains+Mono:wght@400;500;700&#038;family=Plus+Jakarta+Sans:wght@400;600;700;800&#038;display=swap\" rel=\"stylesheet\">\n    <style>\n        :root {\n            --accent: #e8600a;\n            --accent-light: #fff3ec;\n            --accent-mid: #fde3cc;\n            --dark: #111827;\n            --text: #1a1a1a;\n            --text-muted: #4b5563;\n            --border: #e5e7eb;\n            --green-bg: #f0fdf4;\n            --green-border: #16a34a;\n            --blue-bg: #eff6ff;\n            --blue-border: #3b82f6;\n        }\n\n        body {\n            margin: 0;\n            padding: 0;\n            font-family: 'DM Sans', sans-serif;\n            color: var(--text);\n            background: #fff;\n            line-height: 1.6;\n        }\n\n        .inner-content {\n            padding: 0 0px;\n        }\n\n        @media (max-width: 768px) {\n            .inner-content { padding: 0 10px; 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}\n\n        sub, sup { font-size: 70%; line-height: 0; position: relative; vertical-align: baseline; }\n        sup { top: -0.5em; }\n        sub { bottom: -0.25em; }\n    <\/style>\n<\/head>\n<body>\n\n<div class=\"inner-content\">\n    <div class=\"section-header\">\n        <div class=\"badge\">01<\/div>\n        <h2>Introduction to Structure of Atom Class 11<\/h2>\n    <\/div>\n\n    <p>Understanding the <strong>Structure of Atom class 11<\/strong> is the foundation of modern chemistry. While Dalton initially proposed that atoms were indivisible, the late 19<sup>th<\/sup> and early 20<sup>th<\/sup> centuries revealed a complex internal world. For NEET aspirants, this chapter transitions from classical physics to quantum mechanics, explaining how subatomic particles arrange themselves to dictate chemical behavior. This knowledge is essential for mastering chemical bonding, periodicity, and reaction mechanisms.<\/p>\n\n    <div class=\"links-box\">\n        <span class=\"links-title\">Related Study Resources<\/span>\n        <a href=\"https:\/\/ksquareinstitute.in\/blog\/organic-chemistry-strategy-neet\/\">Organic Chemistry Strategy for NEET<\/a>\n        <a href=\"https:\/\/ksquareinstitute.in\/blog\/neet-physics-survival-kit-2026\/\">NEET Physics Survival Kit 2026<\/a>\n    <\/div>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">02<\/div>\n        <h2>Discovery of Subatomic Particles<\/h2>\n    <\/div>\n\n    <p>The transition from a solid-sphere model to a structured atom began with the discovery of electrons, protons, and neutrons. These discoveries proved that the atom is composed of smaller, charged entities.<\/p>\n\n    <div class=\"mini-cards\">\n        <div class=\"card\">\n            <span class=\"card-title\">THE ELECTRON (e<sup>&#8211;<\/sup>)<\/span>\n            <p class=\"card-text\">Discovered by J.J. Thomson via Cathode Ray experiments. He determined the charge-to-mass ratio (e\/m) to be 1.758820 \u00d7 10<sup>11<\/sup> C kg<sup>-1<\/sup>.<\/p>\n        <\/div>\n        <div class=\"card\">\n            <span class=\"card-title\">THE NEUTRON (n)<\/span>\n            <p class=\"card-text\">Discovered by James Chadwick in 1932 by bombarding Beryllium with alpha particles. Neutrons are neutral particles with mass slightly greater than protons.<\/p>\n        <\/div>\n    <\/div>\n\n    <div class=\"table-wrapper\">\n        <table>\n            <thead>\n                <tr>\n                    <th>Particle<\/th>\n                    <th>Symbol<\/th>\n                    <th>Absolute Charge (C)<\/th>\n                    <th>Mass (kg)<\/th>\n                <\/tr>\n            <\/thead>\n            <tbody>\n                <tr>\n                    <td>Electron<\/td>\n                    <td>e<sup>&#8211;<\/sup><\/td>\n                    <td>-1.6022 \u00d7 10<sup>-19<\/sup><\/td>\n                    <td>9.10939 \u00d7 10<sup>31<\/sup><\/td>\n                <\/tr>\n                <tr>\n                    <td>Proton<\/td>\n                    <td>p<sup>+<\/sup><\/td>\n                    <td>+1.6022 \u00d7 10<sup>-19<\/sup><\/td>\n                    <td>1.67262 \u00d7 10<sup>-27<\/sup><\/td>\n                <\/tr>\n                <tr>\n                    <td>Neutron<\/td>\n                    <td>n<\/td>\n                    <td>0<\/td>\n                    <td>1.67493 \u00d7 10<sup>-27<\/sup><\/td>\n                <\/tr>\n            <\/tbody>\n        <\/table>\n    <\/div>\n\n    <div class=\"callout callout-warning\">\n        <span class=\"pill pill-warn\">WARN<\/span>\n        <p>Do not confuse Anode Rays (Canal Rays) with Cathode Rays. Anode rays depend on the nature of the gas present in the discharge tube, while Cathode rays do not.<\/p>\n    <\/div>\n\n    <a href=\"https:\/\/courses.ksquare.co.in\/new-courses\/3-mission-180-neet-physics-rankers-batch\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" style=\"display:block; margin-bottom:20px;\">\n        <img decoding=\"async\" src=\"https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/03\/Course-Poromo-Banner-scaled.png\" alt=\"Mission 180 NEET Physics Rankers Batch - KSquare Career Institute\" style=\"width:100%; height:auto; border-radius:10px; display:block;\">\n    <\/a>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">03<\/div>\n        <h2>Evolution of Atomic Models<\/h2>\n    <\/div>\n\n    <p>The <strong>Structure of Atom class 11<\/strong> curriculum follows the historical timeline of atomic models, highlighting how each new discovery refined our understanding.<\/p>\n\n    <h3>Rutherford\u2019s Nuclear Model<\/h3>\n    <p>Rutherford&#8217;s Gold Foil Experiment disproved the Thomson &#8220;Plum Pudding&#8221; model. He concluded that most of the atom&#8217;s mass and positive charge is concentrated in a tiny &#8220;nucleus,&#8221; while electrons move around it. However, classical physics suggested that such electrons should lose energy and spiral into the nucleus, making the atom unstable.<\/p>\n\n    <h3>Bohr\u2019s Model of Hydrogen Atom<\/h3>\n    <p>Niels Bohr solved the stability issue by proposing quantized orbits. Electrons move in specific paths where they do not radiate energy unless they jump between levels.<\/p>\n\n    <span class=\"formula-label\">BOHR\u2019S RADIUS AND ENERGY FORMULAS<\/span>\n    <div class=\"formula-dark\">\n        Radius (r<sub>n<\/sub>) = 52.9 (n<sup>2<\/sup>\/Z) pm<br>\n        Energy (E<sub>n<\/sub>) = -2.18 \u00d7 10<sup>-18<\/sup> (Z<sup>2<\/sup>\/n<sup>2<\/sup>) J\/atom<br>\n        Velocity (v<sub>n<\/sub>) = 2.18 \u00d7 10<sup>6<\/sup> (Z\/n) m\/s\n    <\/div>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">04<\/div>\n        <h2>Dual Nature of Radiation and Matter<\/h2>\n    <\/div>\n\n    <p>The development of the quantum mechanical model was triggered by two major concepts: the dual nature of light\/matter and Heisenberg&#8217;s Uncertainty Principle.<\/p>\n\n    <div class=\"mini-cards\">\n        <div class=\"card\">\n            <span class=\"card-title\">DE BROGLIE WAVELENGTH<\/span>\n            <p class=\"card-text\">Every moving object has a wave character. The wavelength (\u03bb) is inversely proportional to its momentum (p).<\/p>\n        <\/div>\n        <div class=\"card\">\n            <span class=\"card-title\">PHOTOELECTRIC EFFECT<\/span>\n            <p class=\"card-text\">Einstein showed light behaves as particles called &#8220;photons.&#8221; Energy (E) = h\u03bd, where h is Planck&#8217;s constant.<\/p>\n        <\/div>\n    <\/div>\n\n    <span class=\"formula-label\">QUANTUM MECHANICAL FORMULAS<\/span>\n    <div class=\"formula-orange\">\n        \u03bb = h \/ mv = h \/ p<br>\n        \u0394x \u00d7 \u0394p \u2265 h \/ 4\u03c0<br>\n        E = h\u03bd = hc \/ \u03bb\n    <\/div>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">05<\/div>\n        <h2>Atomic Spectrum and Hydrogen Series<\/h2>\n    <\/div>\n\n    <p>When electrons jump between orbits, they emit radiation of specific wavelengths, creating a line spectrum. The hydrogen spectrum consists of several series identified by the lower energy level (n<sub>1<\/sub>).<\/p>\n\n    <div class=\"table-wrapper\">\n        <table>\n            <thead>\n                <tr>\n                    <th>Series<\/th>\n                    <th>n<sub>1<\/sub><\/th>\n                    <th>n<sub>2<\/sub><\/th>\n                    <th>Spectral Region<\/th>\n                <\/tr>\n            <\/thead>\n            <tbody>\n                <tr>\n                    <td>Lyman<\/td>\n                    <td>1<\/td>\n                    <td>2, 3, 4&#8230;<\/td>\n                    <td>Ultraviolet (UV)<\/td>\n                <\/tr>\n                <tr>\n                    <td>Balmer<\/td>\n                    <td>2<\/td>\n                    <td>3, 4, 5&#8230;<\/td>\n                    <td>Visible<\/td>\n                <\/tr>\n                <tr>\n                    <td>Paschen<\/td>\n                    <td>3<\/td>\n                    <td>4, 5, 6&#8230;<\/td>\n                    <td>Infrared<\/td>\n                <\/tr>\n                <tr>\n                    <td>Brackett<\/td>\n                    <td>4<\/td>\n                    <td>5, 6, 7&#8230;<\/td>\n                    <td>Infrared<\/td>\n                <\/tr>\n                <tr>\n                    <td>Pfund<\/td>\n                    <td>5<\/td>\n                    <td>6, 7, 8&#8230;<\/td>\n                    <td>Infrared<\/td>\n                <\/tr>\n            <\/tbody>\n        <\/table>\n    <\/div>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">06<\/div>\n        <h2>Quantum Numbers: The Address of an Electron<\/h2>\n    <\/div>\n\n    <p>In the quantum mechanical <strong>Structure of Atom class 11<\/strong>, we describe electrons using four quantum numbers. These values define the energy, size, shape, and orientation of orbitals.<\/p>\n\n    <div class=\"mini-cards\">\n        <div class=\"card\">\n            <span class=\"card-title\">PRINCIPAL (n)<\/span>\n            <p class=\"card-text\">Determines the main shell\/energy level and size. Values: 1, 2, 3&#8230;<\/p>\n        <\/div>\n        <div class=\"card\">\n            <span class=\"card-title\">AZIMUTHAL (l)<\/span>\n            <p class=\"card-text\">Determines the shape of the subshell. l ranges from 0 to (n-1). (0=s, 1=p, 2=d, 3=f)<\/p>\n        <\/div>\n        <div class=\"card\">\n            <span class=\"card-title\">MAGNETIC (m<sub>l<\/sub>)<\/span>\n            <p class=\"card-text\">Determines spatial orientation. Range: -l to +l including zero.<\/p>\n        <\/div>\n        <div class=\"card\">\n            <span class=\"card-title\">SPIN (m<sub>s<\/sub>)<\/span>\n            <p class=\"card-text\">Determines the direction of electron spin. Values: +1\/2 or -1\/2.<\/p>\n        <\/div>\n    <\/div>\n\n    <div class=\"callout callout-tip\">\n        <span class=\"pill pill-tip\">TIP<\/span>\n        <p>Number of orbitals in a shell = n<sup>2<\/sup>. Maximum number of electrons in a shell = 2n<sup>2<\/sup>.<\/p>\n    <\/div>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">07<\/div>\n        <h2>Electronic Configuration and Principles<\/h2>\n    <\/div>\n\n    <p>Filling electrons into orbitals follows three fundamental rules. Mastery of these is critical for NEET questions on transition elements and anomalous configurations.<\/p>\n\n    <ul>\n        <li><strong>Aufbau Principle:<\/strong> Electrons enter orbitals in increasing order of their energies (n+l rule).<\/li>\n        <li><strong>Pauli Exclusion Principle:<\/strong> No two electrons in an atom can have the same set of four quantum numbers.<\/li>\n        <li><strong>Hund&#8217;s Rule of Maximum Multiplicity:<\/strong> Pairing of electrons in p, d, or f orbitals doesn&#8217;t happen until each orbital is singly occupied.<\/li>\n    <\/ul>\n\n    <span class=\"formula-label\">TOTAL NODES CALCULATION<\/span>\n    <div class=\"formula-dark\">\n        Radial Nodes = n &#8211; l &#8211; 1<br>\n        Angular Nodes = l<br>\n        Total Nodes = n &#8211; 1\n    <\/div>\n\n    <div class=\"download-wrapper\">\n        <a href=\"https:\/\/ksquareinstitute.in\/free-study-material\/\" rel=\"nofollow noopener noreferrer\" class=\"download-btn\">\n            <svg width=\"20\" height=\"20\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v4\"><\/path><polyline points=\"7 10 12 15 17 10\"><\/polyline><line x1=\"12\" y1=\"15\" x2=\"12\" y2=\"3\"><\/line><\/svg>\n            Download Atomic Structure Formula Sheet\n        <\/a>\n    <\/div>\n\n    <a href=\"https:\/\/ksquareinstitute.in\/neet-2026-rank-predictor\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" style=\"display:block; margin-bottom:20px;\">\n        <img decoding=\"async\" src=\"https:\/\/ksquareinstitute.in\/blog\/wp-content\/uploads\/2026\/03\/neet-2026-college-and-rank-predictor-scaled.png\" alt=\"NEET 2026 Rank Predictor - KSquare Career Institute\" style=\"width:100%; height:auto; border-radius:10px; display:block;\">\n    <\/a>\n\n    <div class=\"section-header\">\n        <div class=\"badge\">08<\/div>\n        <h2>Stability of Half-Filled and Fully-Filled Orbitals<\/h2>\n    <\/div>\n\n    <p>Certain elements like Chromium (Cr, Z=24) and Copper (Cu, Z=29) show anomalous configurations. This is due to the extra stability of half-filled and fully-filled subshells, attributed to <strong>Symmetry<\/strong> and <strong>Exchange Energy<\/strong>.<\/p>\n\n    <div class=\"formula-orange\">\n        Cr: [Ar] 3d<sup>5<\/sup> 4s<sup>1<\/sup> (Instead of 3d<sup>4<\/sup> 4s<sup>2<\/sup>)<br>\n        Cu: [Ar] 3d<sup>10<\/sup> 4s<sup>1<\/sup> (Instead of 3d<sup>9<\/sup> 4s<sup>2<\/sup>)\n    <\/div>\n\n    <div class=\"links-box\">\n        <span class=\"links-title\">Master Biology for NEET<\/span>\n        <a href=\"https:\/\/ksquareinstitute.in\/blog\/neet-biology-tricks-for-exams\/\">NEET Biology Tricks for Exams<\/a>\n        <a href=\"https:\/\/ksquareinstitute.in\/blog\/score-340-in-neet-biology\/\">Score 340 in NEET Biology<\/a>\n        <a href=\"https:\/\/ksquareinstitute.in\/blog\/top-10-tricky-neet-biology-diagrams\/\">Top 10 Tricky NEET Biology Diagrams<\/a>\n    <\/div>\n\n    <div class=\"revision-box\">\n        <h3>Revision Checklist: Structure of Atom<\/h3>\n        <ul>\n            <li>Mass of electron is approx. 1\/1837 times the mass of a proton.<\/li>\n            <li>Rutherford discovered the nucleus; Chadwick discovered the neutron.<\/li>\n            <li>Energy is emitted or absorbed only when an electron jumps between orbits.<\/li>\n            <li>Balmer series is the only series in the visible region for Hydrogen.<\/li>\n            <li>The n+l rule determines the energy of an orbital.<\/li>\n            <li>Angular momentum of an electron is quantized: mvr = nh \/ 2\u03c0.<\/li>\n            <li>The shape of s-orbital is spherical; p-orbital is dumbbell.<\/li>\n            <li>Exchange energy is higher for half-filled\/fully-filled configurations.<\/li>\n            <li>Threshold frequency (\u03bd<sub>0<\/sub>) is the minimum frequency for photoelectric effect.<\/li>\n            <li>Wavelength (\u03bb) = h \/ \u221a(2mKE)<\/li>\n        <\/ul>\n    <\/div>\n\n    <div class=\"faq-section\">\n        <div class=\"section-header\">\n            <div class=\"badge\">09<\/div>\n            <h2>Frequently Asked Questions<\/h2>\n        <\/div>\n\n        <details>\n            <summary>Why can&#8217;t we specify the exact path of an electron?<\/summary>\n            <div class=\"faq-content\">According to Heisenberg\u2019s Uncertainty Principle, it is impossible to determine both the exact position and momentum of a subatomic particle simultaneously. We can only define &#8220;Orbitals&#8221; as regions of high probability.<\/div>\n        <\/details>\n        <details>\n            <summary>What are isotopes, isobars, and isotones?<\/summary>\n            <div class=\"faq-content\">Isotopes: Same Z, different A (e.g., Protium, Deuterium). Isobars: Same A, different Z (e.g., Ar-40 and Ca-40). Isotones: Same number of neutrons (e.g., C-14 and O-16).<\/div>\n        <\/details>\n        <details>\n            <summary>What is the physical significance of \u03c8 and \u03c8\u00b2?<\/summary>\n            <div class=\"faq-content\">\u03c8 (Wave function) represents the amplitude of the electron wave. \u03c8\u00b2 (Probability density) represents the probability of finding an electron at a specific point in space.<\/div>\n        <\/details>\n        <details>\n            <summary>How many radial nodes are there in a 4p orbital?<\/summary>\n            <div class=\"faq-content\">Using formula n &#8211; l &#8211; 1: For 4p, n=4 and l=1. Nodes = 4 &#8211; 1 &#8211; 1 = 2 radial nodes.<\/div>\n        <\/details>\n        <details>\n            <summary>What is the &#8220;Black Body Radiation&#8221; concept?<\/summary>\n            <div class=\"faq-content\">An ideal body that emits and absorbs radiations of all frequencies. It helped Planck develop the Quantum Theory of light.<\/div>\n        <\/details>\n        <details>\n            <summary>Why is the 4s orbital filled before 3d?<\/summary>\n            <div class=\"faq-content\">Based on the (n+l) rule: For 4s, n+l = 4+0 = 4. For 3d, n+l = 3+2 = 5. Lower (n+l) value means lower energy.<\/div>\n        <\/details>\n    <\/div>\n\n    <div class=\"cta\">\n        <h2>Ready to Master NEET Chemistry?<\/h2>\n        <p>Join the Mission 180 NEET Physics &#038; Chemistry Rankers Batch for conceptual clarity and expert-led problem-solving sessions. Start your journey to a top medical college today.<\/p>\n        <div class=\"cta-btns\">\n            <a href=\"https:\/\/courses.ksquare.co.in\/new-courses\/3-mission-180-neet-physics-rankers-batch\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" class=\"btn-solid\">Join Mission 180 Batch<\/a>\n            <a href=\"https:\/\/ksquareinstitute.in\/free-study-material\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" class=\"btn-outline\">Explore Free Materials<\/a>\n        <\/div>\n    <\/div>\n<\/div>\n\n<\/body>\n<\/html>\n\n\n\n<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n  <meta charset=\"UTF-8\">\n  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n  <title>Table of Contents \u2014 Chemistry Class 11<\/title>\n  \n  <!-- Google Fonts Import -->\n  <link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n  <link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\n  <link href=\"https:\/\/fonts.googleapis.com\/css2?family=DM+Sans:ital,opsz,wght@0,9..40,100..1000;1,9..40,100..1000&#038;family=Plus+Jakarta+Sans:ital,wght@0,200..800;1,200..800&#038;display=swap\" rel=\"stylesheet\">\n  \n  <style>\n    \/* Scoped wrapper using a unique ID to prevent CSS conflicts. *\/\n    #chemistry-toc-wrapper {\n      font-family: 'DM Sans', sans-serif;\n      width: 100%;\n      margin: 0;\n      padding: 60px 0;\n      color: #111;\n      background: #fff;\n      -webkit-font-smoothing: antialiased;\n    }\n\n    #chemistry-toc-wrapper .container-inner {\n      width: 100%;\n      margin: 0 auto;\n      padding: 0; \/* No left\/right padding for edge-to-edge look *\/\n    }\n\n    #chemistry-toc-wrapper h1 {\n      font-family: 'Plus Jakarta Sans', sans-serif;\n      font-size: 0.85rem;\n      font-weight: 700;\n      color: #71717a;\n      margin: 0 0 8px;\n      letter-spacing: 0.1em;\n      text-transform: uppercase;\n      padding-left: 16px; \n    }\n\n    #chemistry-toc-wrapper h2 {\n      font-family: 'Plus Jakarta Sans', sans-serif;\n      font-size: 2.25rem;\n      font-weight: 800;\n      margin: 0 0 48px;\n      letter-spacing: -0.02em;\n      color: #09090b;\n      padding-left: 16px;\n    }\n\n    #chemistry-toc-wrapper table {\n      width: 100%;\n      border-collapse: collapse;\n      border-spacing: 0;\n      border-top: 1px solid #e4e4e7;\n      border-bottom: 1px solid #e4e4e7;\n    }\n\n    #chemistry-toc-wrapper tr {\n      border-bottom: 1px solid #e4e4e7;\n      transition: all 0.2s ease;\n    }\n\n    #chemistry-toc-wrapper tr:hover {\n      background-color: #f8fafc;\n    }\n\n    #chemistry-toc-wrapper tr:last-child {\n      border-bottom: none;\n    }\n\n    #chemistry-toc-wrapper td {\n      padding: 24px 16px;\n      vertical-align: middle;\n      font-size: 1.05rem;\n      font-weight: 500;\n      border-right: 1px solid #e4e4e7;\n    }\n\n    #chemistry-toc-wrapper td:last-child {\n      border-right: none;\n    }\n\n    \/* First column (Numbers) alignment and padding *\/\n    #chemistry-toc-wrapper td:first-child {\n      color: #a1a1aa;\n      font-size: 0.9rem;\n      width: 70px;\n      font-weight: 400;\n      font-variant-numeric: tabular-nums;\n      text-align: center;\n      padding-left: 10px;\n    }\n\n    \/* Middle column (Chapter Name) alignment and padding *\/\n    #chemistry-toc-wrapper td:nth-child(2) {\n      padding-left: 24px;\n      color: #18181b;\n    }\n\n    \/* Last column (Button) alignment and padding *\/\n    #chemistry-toc-wrapper td:last-child {\n      text-align: right;\n      width: 180px;\n      padding-right: 16px;\n    }\n\n    \/* Button Styling *\/\n    #chemistry-toc-wrapper a.go {\n      display: inline-block;\n      font-family: 'Plus Jakarta Sans', sans-serif;\n      font-size: 0.75rem;\n      font-weight: 800;\n      padding: 12px 24px;\n      border: 1.5px solid #18181b;\n      border-radius: 8px;\n      color: #18181b;\n      text-decoration: none;\n      letter-spacing: 0.05em;\n      text-transform: uppercase;\n      transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);\n      white-space: nowrap;\n    }\n\n    #chemistry-toc-wrapper a.go:hover {\n      background: #18181b;\n      color: #ffffff;\n      transform: translateY(-2px);\n      box-shadow: 0 4px 12px rgba(24, 24, 27, 0.15);\n    }\n\n    \/* Responsive adjustments *\/\n    @media (max-width: 768px) {\n      #chemistry-toc-wrapper h2 {\n        font-size: 1.75rem;\n        margin-bottom: 32px;\n      }\n      #chemistry-toc-wrapper td {\n        padding: 18px 12px;\n        font-size: 0.95rem;\n      }\n    }\n  <\/style>\n<\/head>\n<body>\n\n<div id=\"chemistry-toc-wrapper\">\n  <div class=\"container-inner\">\n    <h1>Table of Contents<\/h1>\n    <h2>Chemistry &mdash; Class 11<\/h2>\n    \n    <table>\n      <tr><td>01<\/td><td>Some Basic Concepts of Chemistry<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/some-basic-concepts-of-chemistry-class-11\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>02<\/td><td>Structure of Atom<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/structure-of-atom-class-11\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>03<\/td><td>Classification of Elements and Periodicity<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/periodic-table-class-11-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>04<\/td><td>Chemical Bonding and Molecular Structure<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/chemical-bonding-class-11-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>05<\/td><td>Thermodynamics<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/thermodynamics-chemistry-class-11-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>06<\/td><td>Equilibrium<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/equilibrium-chemistry-class-11-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>07<\/td><td>Redox Reactions<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/redox-reactions-chemistry-class-11-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>08<\/td><td>Organic Chemistry &mdash; Basic Principles<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/organic-chemistry-basic-principles-class-11\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>09<\/td><td>Hydrocarbons<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/hydrocarbons-class-11-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n    <\/table>\n  <\/div>\n<\/div>\n\n<\/body>\n<\/html>\n","protected":false},"excerpt":{"rendered":"<p>01 Introduction to Structure of Atom Class 11 Understanding the Structure of Atom class 11 is the foundation of modern chemistry. While Dalton initially proposed that atoms were indivisible, the late 19th and early 20th centuries revealed a complex internal world. For NEET aspirants, this chapter transitions from classical physics to quantum mechanics, explaining how [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[127],"tags":[304,303,305,302,301],"class_list":["post-4010","post","type-post","status-publish","format-standard","hentry","category-free-study-material","tag-atomic-structure-notes","tag-class-11-chemistry-chapter-2","tag-electronic-configuration","tag-quantum-numbers-class-11","tag-structure-of-atom-class-11"],"blocksy_meta":{"page_structure_type":"type-1","styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":6}},"_links":{"self":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/4010","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/comments?post=4010"}],"version-history":[{"count":2,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/4010\/revisions"}],"predecessor-version":[{"id":4233,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/4010\/revisions\/4233"}],"wp:attachment":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/media?parent=4010"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/categories?post=4010"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/tags?post=4010"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}