{"id":4004,"date":"2026-03-30T07:01:25","date_gmt":"2026-03-30T07:01:25","guid":{"rendered":"https:\/\/ksquareinstitute.in\/blog\/?p=4004"},"modified":"2026-04-03T12:27:51","modified_gmt":"2026-04-03T12:27:51","slug":"nuclei-class-12-notes","status":"publish","type":"post","link":"https:\/\/ksquareinstitute.in\/blog\/nuclei-class-12-notes\/","title":{"rendered":"Nuclei Class 12 Notes for NEET: Formulas, Binding Energy &amp; Radioactivity Guide"},"content":{"rendered":"\n<style>\n@import url('https:\/\/fonts.googleapis.com\/css2?family=DM+Sans:ital,wght@0,300;0,400;0,500;0,600;1,400&family=JetBrains+Mono:wght@400;500;700&family=Plus+Jakarta+Sans:wght@400;600;700;800&display=swap');\n\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\nbody {\n    font-family: 'DM Sans', sans-serif;\n    color: var(--text);\n    line-height: 1.7;\n    margin: 0;\n    padding: 0;\n    -webkit-font-smoothing: antialiased;\n}\n\nh2 {\n    font-family: 'Plus Jakarta Sans', sans-serif;\n    font-size: 26px;\n    font-weight: 700;\n    color: var(--dark);\n    margin: 0;\n    line-height: 1.2;\n}\n\nh3 {\n    font-family: 'Plus Jakarta Sans', sans-serif;\n    font-size: 20px;\n    font-weight: 700;\n    color: var(--dark);\n    margin: 28px 0 14px 0;\n}\n\n.content-wrapper {\n    width: 100%;\n    margin: 0 auto;\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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font-size: 14px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.5px; }\n.links-box a { display: block; color: var(--accent); text-decoration: none; font-weight: 600; font-size: 15px; margin-bottom: 8px; }\n.links-box a:hover { text-decoration: underline; }\n\n.download-btn {\n    background: var(--dark);\n    color: white;\n    padding: 12px 24px;\n    border-radius: 8px;\n    text-decoration: none;\n    display: inline-flex;\n    align-items: center;\n    gap: 10px;\n    font-weight: 700;\n    font-size: 14px;\n}\n\n@media (max-width: 640px) {\n    .grid-cards, .revision-list { grid-template-columns: 1fr; }\n    .cta-btns { flex-direction: column; }\n}\n<\/style>\n\n<div class=\"content-wrapper\">\n<div class=\"inner-content\">\n\n<div class=\"section-header\">\n    <div class=\"badge\">01<\/div>\n    <h2>Introduction to Nucleus and Nuclei class 12 notes<\/h2>\n<\/div>\n\n<p>The study of <strong>Nuclei class 12 notes<\/strong> forms the backbone of modern nuclear physics. Every atom contains a tiny, dense core known as the nucleus, discovered by Ernest Rutherford. While the atom itself is mostly empty space, the nucleus holds more than 99.9% of its mass. In these <strong>Nuclei class 12 notes<\/strong>, we explore the composition, size, and forces that hold the core together.<\/p>\n\n<div class=\"grid-cards\">\n    <div class=\"mini-card\">\n        <span class=\"card-title\">ATOMIC NUMBER (Z)<\/span>\n        <p class=\"card-body\">The number of protons in the nucleus. It defines the identity of the element.<\/p>\n    <\/div>\n    <div class=\"mini-card\">\n        <span class=\"card-title\">MASS NUMBER (A)<\/span>\n        <p class=\"card-body\">The total number of nucleons (protons + neutrons). Mathematically: A = Z + N.<\/p>\n    <\/div>\n<\/div>\n\n<div class=\"callout tip\">\n    <div class=\"pill pill-tip\">TIP<\/div>\n    <div>Nuclear notation is represented as <sub>Z<\/sub>X<sup>A<\/sup>, where X is the chemical symbol, A is the mass number, and Z is the atomic number.<\/div>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">02<\/div>\n    <h2>Nuclear Size and Constant Density<\/h2>\n<\/div>\n\n<p>Experimental data shows that the nucleus is not a point but has a specific volume. The radius of a nucleus is related to its mass number through an empirical relationship. Interestingly, the density of nuclear matter is nearly constant for all elements, roughly 2.3 \u00d7 10<sup>17<\/sup> kg\/m<sup>3<\/sup>.<\/p>\n\n<div class=\"formula-dark\">\n    <span class=\"formula-label\">NUCLEAR RADIUS FORMULA<\/span>\n    <p class=\"formula-mono-orange\">R = R<sub>0<\/sub> A<sup>1\/3<\/sup><\/p>\n    <p class=\"formula-mono-orange\">Where R<sub>0<\/sub> \u2248 1.2 \u00d7 10<sup>-15<\/sup> m (1.2 fm)<\/p>\n<\/div>\n\n<div class=\"formula-orange-box\">\n    <span class=\"formula-label\">NUCLEAR DENSITY INSIGHT<\/span>\n    <p class=\"formula-mono-red\">Density (\u03c1) = Mass \/ Volume<\/p>\n    <p class=\"formula-mono-red\">\u03c1 \u2248 3m \/ (4\u03c0 R<sub>0<\/sub><sup>3<\/sup>)<\/p>\n    <p class=\"formula-mono-red\">Since \u03c1 is independent of A, all nuclei have the same density.<\/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>Atomic Masses, Isotopes, and Isobars<\/h2>\n<\/div>\n\n<p>In nuclear physics, we use the atomic mass unit (amu) because standard units like kilograms are too large. One amu is defined as 1\/12th of the mass of a Carbon-12 atom.<\/p>\n\n<table>\n    <thead>\n        <tr>\n            <th>Term<\/th>\n            <th>Definition<\/th>\n            <th>Example<\/th>\n        <\/tr>\n    <\/thead>\n    <tbody>\n        <tr>\n            <td>Isotopes<\/td>\n            <td>Same Z, Different A<\/td>\n            <td><sub>1<\/sub>H<sup>1<\/sup>, <sub>1<\/sub>H<sup>2<\/sup>, <sub>1<\/sub>H<sup>3<\/sup><\/td>\n        <\/tr>\n        <tr>\n            <td>Isobars<\/td>\n            <td>Same A, Different Z<\/td>\n            <td><sub>18<\/sub>Ar<sup>40<\/sup>, <sub>20<\/sub>Ca<sup>40<\/sup><\/td>\n        <\/tr>\n        <tr>\n            <td>Isotones<\/td>\n            <td>Same number of Neutrons<\/td>\n            <td><sub>15<\/sub>P<sup>31<\/sup>, <sub>16<\/sub>S<sup>32<\/sup><\/td>\n        <\/tr>\n    <\/tbody>\n<\/table>\n\n<div class=\"section-header\">\n    <div class=\"badge\">04<\/div>\n    <h2>Mass Defect and Binding Energy class 12<\/h2>\n<\/div>\n\n<p>A curious fact of the <strong>Nuclei class 12 notes<\/strong> is that the mass of a stable nucleus is always less than the sum of the masses of its individual nucleons. This &#8220;missing mass&#8221; is called the mass defect (\u0394m), which is converted into binding energy.<\/p>\n\n<div class=\"formula-dark\">\n    <span class=\"formula-label\">MASS DEFECT CALCULATION<\/span>\n    <p class=\"formula-mono-orange\">\u0394m = [Z\u00b7m<sub>p<\/sub> + (A &#8211; Z)\u00b7m<sub>n<\/sub>] &#8211; M<sub>nucleus<\/sub><\/p>\n<\/div>\n\n<div class=\"formula-orange-box\">\n    <span class=\"formula-label\">BINDING ENERGY (E<sub>b<\/sub>)<\/span>\n    <p class=\"formula-mono-red\">E<sub>b<\/sub> = \u0394m \u00b7 c<sup>2<\/sup><\/p>\n    <p class=\"formula-mono-red\">In MeV: E<sub>b<\/sub> = \u0394m(amu) \u00d7 931.5 MeV<\/p>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">05<\/div>\n    <h2>The Binding Energy Curve and Stability<\/h2>\n<\/div>\n\n<p>The binding energy per nucleon (E<sub>bn<\/sub>) is a direct indicator of nuclear stability. By plotting E<sub>bn<\/sub> against the mass number (A), we observe a specific trend that explains nuclear reactions.<\/p>\n\n<ul>\n    <li><strong>Maximum Stability:<\/strong> E<sub>bn<\/sub> is highest for A \u2248 56 (Iron, Fe), making it the most stable nucleus.<\/li>\n    <li><strong>Lighter Nuclei:<\/strong> Have lower E<sub>bn<\/sub> and tend to undergo <strong>Nuclear Fusion<\/strong> to gain stability.<\/li>\n    <li><strong>Heavier Nuclei:<\/strong> Have decreasing E<sub>bn<\/sub> due to Coulombic repulsion and tend to undergo <strong>Nuclear Fission<\/strong>.<\/li>\n<\/ul>\n\n<div class=\"section-header\">\n    <div class=\"badge\">06<\/div>\n    <h2>Radioactivity and Spontaneous Decay<\/h2>\n<\/div>\n\n<p>Radioactivity is the spontaneous emission of particles from an unstable nucleus. It is a purely nuclear phenomenon and is independent of external conditions like temperature or pressure. This is a critical section of <strong>Nuclei class 12 notes<\/strong> for NEET.<\/p>\n\n<div class=\"grid-cards\">\n    <div class=\"mini-card\">\n        <span class=\"card-title\">ALPHA (\u03b1) DECAY<\/span>\n        <p class=\"card-body\">Emission of a Helium nucleus. A decreases by 4, Z decreases by 2.<\/p>\n    <\/div>\n    <div class=\"mini-card\">\n        <span class=\"card-title\">BETA (\u03b2) DECAY<\/span>\n        <p class=\"card-body\">Emission of an electron or positron. A remains constant, Z changes by 1.<\/p>\n    <\/div>\n<\/div>\n\n<div class=\"callout warning\">\n    <div class=\"pill pill-warning\">WARN<\/div>\n    <div>Gamma (\u03b3) decay involves the emission of high-energy photons. In \u03b3-decay, both Z and A remain unchanged as the nucleus merely transitions to a lower energy state.<\/div>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">07<\/div>\n    <h2>Radioactive Decay Law and Activity<\/h2>\n<\/div>\n\n<p>The rate at which a radioactive sample decays is proportional to the number of nuclei present at that instant. This leads to the exponential decay law.<\/p>\n\n<div class=\"formula-dark\">\n    <span class=\"formula-label\">DECAY EQUATION<\/span>\n    <p class=\"formula-mono-orange\">N = N<sub>0<\/sub> e<sup>-\u03bbt<\/sup><\/p>\n    <p class=\"formula-mono-orange\">Activity (A) = \u03bbN<\/p>\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>Half-Life and Mean Life Concepts<\/h2>\n<\/div>\n\n<p>Two time-related parameters are crucial in <strong>Nuclei class 12 notes<\/strong>: Half-life (the time for 50% decay) and Mean life (the average lifetime of a nucleus).<\/p>\n\n<div class=\"formula-orange-box\">\n    <span class=\"formula-label\">TIME RELATIONS<\/span>\n    <p class=\"formula-mono-red\">T<sub>1\/2<\/sub> = 0.693 \/ \u03bb<\/p>\n    <p class=\"formula-mono-red\">Mean Life (\u03c4) = 1 \/ \u03bb<\/p>\n    <p class=\"formula-mono-red\">Relation: T<sub>1\/2<\/sub> = 0.693 \u03c4<\/p>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">09<\/div>\n    <h2>Nuclear Fission and Fusion Reactions<\/h2>\n<\/div>\n\n<p>Nuclear reactions involve the transformation of nuclei and the release of immense energy based on Einstein&#8217;s mass-energy equivalence.<\/p>\n\n<ul>\n    <li><strong>Nuclear Fission:<\/strong> Splitting of a heavy nucleus (like U-235) into smaller fragments. It is the basis of nuclear power plants.<\/li>\n    <li><strong>Nuclear Fusion:<\/strong> Combining of light nuclei (like Hydrogen) to form a heavier nucleus. It requires extreme temperatures (millions of Kelvin).<\/li>\n<\/ul>\n\n<div class=\"grid-cards\">\n    <div class=\"mini-card\">\n        <span class=\"card-title\">FISSION KEY<\/span>\n        <p class=\"card-body\">Requires neutrons to trigger. Produces more neutrons, leading to a chain reaction.<\/p>\n    <\/div>\n    <div class=\"mini-card\">\n        <span class=\"card-title\">FUSION KEY<\/span>\n        <p class=\"card-body\">The primary energy source for stars, including our Sun. cleaner but harder to achieve on Earth.<\/p>\n    <\/div>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">10<\/div>\n    <h2>Energy Calculations and Numericals<\/h2>\n<\/div>\n\n<p>Numerical problems in <strong>Nuclei class 12 notes<\/strong> usually focus on energy released (Q-value) or mass defect conversions. Remember that energy released in a reaction is the difference between final and initial binding energies.<\/p>\n\n<div class=\"formula-dark\">\n    <span class=\"formula-label\">Q-VALUE CALCULATION<\/span>\n    <p class=\"formula-mono-orange\">Q = (Mass of reactants &#8211; Mass of products) \u00b7 c<sup>2<\/sup><\/p>\n    <p class=\"formula-mono-orange\">If Q > 0, the reaction is exothermic (energy released).<\/p>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">11<\/div>\n    <h2>Common Mistakes to Avoid in Nuclei class 12 notes<\/h2>\n<\/div>\n\n<div class=\"callout warning\">\n    <div class=\"pill pill-warning\">WARN<\/div>\n    <div>1. Confusing Atomic Number (Z) with Mass Number (A) in radius calculations. \n    2. Forgetting to convert amu to kg when calculating energy in Joules (or just use 931.5 MeV for amu). \n    3. Using wrong units for \u03bb; ensure t and \u03bb have compatible time units (e.g., s and s<sup>-1<\/sup>).<\/div>\n<\/div>\n\n<div class=\"revision-box\">\n    <h3>Quick Revision Checklist: Nuclei class 12 notes<\/h3>\n    <ul class=\"revision-list\">\n        <li>Nuclear Radius R = R<sub>0<\/sub> A<sup>1\/3<\/sup><\/li>\n        <li>Density of nucleus is constant (~10<sup>17<\/sup> kg\/m<sup>3<\/sup>)<\/li>\n        <li>1 amu = 931.5 MeV\/c<sup>2<\/sup><\/li>\n        <li>Mass Defect \u0394m = \u03a3m<sub>reactants<\/sub> &#8211; m<sub>nucleus<\/sub><\/li>\n        <li>Binding Energy E<sub>b<\/sub> = \u0394m \u00d7 931.5 MeV<\/li>\n        <li>Activity A = \u03bbN = A<sub>0<\/sub> e<sup>-\u03bbt<\/sup><\/li>\n        <li>Half Life T<sub>1\/2<\/sub> = 0.693 \/ \u03bb<\/li>\n        <li>Mean Life \u03c4 = 1 \/ \u03bb<\/li>\n        <li>Fe-56 has the highest B.E. per nucleon<\/li>\n        <li>Fission involves heavy nuclei; Fusion involves light nuclei<\/li>\n        <li>Radioactivity is a first-order kinetics process<\/li>\n        <li>N \/ N<sub>0<\/sub> = (1\/2)<sup>n<\/sup>, where n = t \/ T<sub>1\/2<\/sub><\/li>\n    <\/ul>\n    <a href=\"#\" rel=\"nofollow noopener noreferrer\" class=\"download-btn\">\n        <svg width=\"18\" height=\"18\" 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 1-2-2v-4\"><\/path><polyline points=\"7 10 12 15 17 10\"><\/polyline><line x1=\"12\" y1=\"15\" x2=\"12\" y2=\"3\"><\/line><\/svg>\n        Download Formula PDF\n    <\/a>\n<\/div>\n\n<div class=\"section-header\">\n    <div class=\"badge\">12<\/div>\n    <h2>FAQs: Nuclei class 12 notes for NEET<\/h2>\n<\/div>\n\n<details>\n    <summary>Is nuclear density the same for Hydrogen and Uranium?<\/summary>\n    <div class=\"faq-answer\">\n        Yes. Since both mass and volume are proportional to the mass number A, the ratio (density) remains constant for all nuclei.\n    <\/div>\n<\/details>\n\n<details>\n    <summary>What determines the stability of a nucleus?<\/summary>\n    <div class=\"faq-answer\">\n        The primary factor is the Binding Energy per Nucleon (E<sub>bn<\/sub>). A higher E<sub>bn<\/sub> means the nucleus is more tightly bound and stable.\n    <\/div>\n<\/details>\n\n<details>\n    <summary>Can we change the half-life of a radioactive substance?<\/summary>\n    <div class=\"faq-answer\">\n        No. Half-life is a characteristic property of a specific isotope and cannot be changed by physical or chemical means.\n    <\/div>\n<\/details>\n\n<details>\n    <summary>What is the Q-value of a nuclear reaction?<\/summary>\n    <div class=\"faq-answer\">\n        It is the net energy released or absorbed during a nuclear reaction. Positive Q means energy is released.\n    <\/div>\n<\/details>\n\n<details>\n    <summary>Why is high temperature needed for nuclear fusion?<\/summary>\n    <div class=\"faq-answer\">\n        High temperature is necessary to give the nuclei enough kinetic energy to overcome the strong electrostatic repulsion (Coulomb barrier) between them.\n    <\/div>\n<\/details>\n\n<div class=\"links-box\">\n    <h4>More NEET Physics Prep<\/h4>\n    <a href=\"https:\/\/ksquareinstitute.in\/blog\/neet-physics-survival-kit-2026\/\">NEET Physics Survival Kit<\/a>\n    <a href=\"https:\/\/ksquareinstitute.in\/blog\/organic-chemistry-strategy-neet\/\">Chemistry Success Strategy<\/a>\n    <a href=\"https:\/\/ksquareinstitute.in\/blog\/neet-biology-tricks-for-exams\/\">Biology Exam Hacks<\/a>\n    <a href=\"https:\/\/ksquareinstitute.in\/blog\/score-340-in-neet-biology\/\">Score 340+ in Bio<\/a>\n<\/div>\n\n<\/div>\n<\/div>\n\n<section class=\"cta-section\">\n    <h2>Master Physics for NEET 2026<\/h2>\n    <p>Get access to specialized <strong>Nuclei class 12 notes<\/strong>, live doubt sessions, and thousands of practice questions in our Rankers Batch.<\/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 btn-white\">Join Rankers Batch<\/a>\n        <a href=\"https:\/\/ksquareinstitute.in\/free-study-material\/\" target=\"_blank\" rel=\"nofollow noopener noreferrer\" class=\"btn btn-outline\">Free Study Material<\/a>\n    <\/div>\n<\/section>\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 Physics Class 12<\/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    #physics-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    #physics-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    #physics-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    #physics-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    #physics-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    #physics-toc-wrapper tr {\n      border-bottom: 1px solid #e4e4e7;\n      transition: all 0.2s ease;\n    }\n\n    #physics-toc-wrapper tr:hover {\n      background-color: #f8fafc;\n    }\n\n    #physics-toc-wrapper tr:last-child {\n      border-bottom: none;\n    }\n\n    #physics-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    #physics-toc-wrapper td:last-child {\n      border-right: none;\n    }\n\n    \/* First column (Numbers) alignment and padding *\/\n    #physics-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    #physics-toc-wrapper td:nth-child(2) {\n      padding-left: 24px;\n      color: #18181b;\n    }\n\n    \/* Last column (Button) alignment and padding *\/\n    #physics-toc-wrapper td:last-child {\n      text-align: right;\n      width: 180px;\n      padding-right: 16px;\n    }\n\n    \/* Button Styling *\/\n    #physics-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    #physics-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      #physics-toc-wrapper h2 {\n        font-size: 1.75rem;\n        margin-bottom: 32px;\n      }\n      #physics-toc-wrapper td {\n        padding: 18px 12px;\n        font-size: 0.95rem;\n      }\n    }\n  <\/style>\n<\/head>\n<body>\n\n<div id=\"physics-toc-wrapper\">\n  <div class=\"container-inner\">\n    <h1>Table of Contents<\/h1>\n    <h2>Physics &mdash; Class 12<\/h2>\n    \n    <table>\n      <tr><td>01<\/td><td>Electric Charges and Fields<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/electric-charges-and-fields-class-12-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>02<\/td><td>Electrostatic Potential and Capacitance<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/electrostatic-potential-and-capacitance-notes-class-12\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>03<\/td><td>Current Electricity<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/current-electricity-class-12-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>04<\/td><td>Moving Charges and Magnetism<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/moving-charges-and-magnetism-class-12-notes\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>05<\/td><td>Magnetism and Matter<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/magnetism-and-matter-class-12-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>06<\/td><td>Electromagnetic Induction<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/electromagnetic-induction-class-12-notes\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>07<\/td><td>Alternating Current<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/alternating-current-class-12-notes\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>08<\/td><td>Electromagnetic Waves<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/electromagnetic-waves-class-12-notes\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>09<\/td><td>Ray Optics and Optical Instruments<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/ray-optics-and-optical-instruments-class-12\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>10<\/td><td>Wave Optics<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/wave-optics-class-12-notes-pdf\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>11<\/td><td>Dual Nature of Radiation and Matter<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/dual-nature-of-radiation-and-matter-class-12\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>12<\/td><td>Atoms<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/atoms-class-12-notes\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>13<\/td><td>Nuclei<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/nuclei-class-12-notes\" target=\"_blank\">Go to page<\/a><\/td><\/tr>\n      <tr><td>14<\/td><td>Semiconductor Electronics<\/td><td><a class=\"go\" href=\"https:\/\/ksquareinstitute.in\/blog\/semiconductor-electronics-class-12-notes\" 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 Nucleus and Nuclei class 12 notes The study of Nuclei class 12 notes forms the backbone of modern nuclear physics. Every atom contains a tiny, dense core known as the nucleus, discovered by Ernest Rutherford. While the atom itself is mostly empty space, the nucleus holds more than 99.9% of its mass. [&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":[282,289,288,285,281,286,287,290,283,284],"class_list":["post-4004","post","type-post","status-publish","format-standard","hentry","category-free-study-material","tag-binding-energy-class-12","tag-binding-energy-curve-class-12","tag-cbse-class-12-physics-nuclei","tag-half-life-formula-class-12","tag-mass-defect-class-12-physics","tag-nuclear-decay-law-class-12","tag-nuclear-fission-and-fusion-class-12","tag-nuclear-reactions-physics","tag-nuclei-class-12-notes","tag-radioactivity-class-12-notes"],"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\/4004","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=4004"}],"version-history":[{"count":2,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/4004\/revisions"}],"predecessor-version":[{"id":4230,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/posts\/4004\/revisions\/4230"}],"wp:attachment":[{"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/media?parent=4004"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/categories?post=4004"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ksquareinstitute.in\/blog\/wp-json\/wp\/v2\/tags?post=4004"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}