The d- and f- Block Elements | Lecture-2 | Density, Enthalpy of Atomisation, Catalysis & Alloys |

Welcome to *ChemClasses with Rahul*! This is **Lecture-2 of the d-Block Elements chapter**, focusing on the most important properties of transition metals for **NEET • JEE • Class 12 Boards**. 📌 Topics Covered in Lecture-2: • Density Trend of Transition Metals • Why density increases across a series and down a group • Reason for highest density in 5d series • Enthalpy of Atomisation / Metallic Bond Strength • Hard Metals (Cr, Mo, W) vs Soft Metals (Zn, Cd, Hg) • Catalytic Properties of Transition Metals • Mechanism of Catalysis (Intermediate complex, adsorption mechanism) • Alloy Formation & Industrial Alloys • Substitutional & Interstitial Mechanism • Interstitial Compounds (Metal + C/N/H/B) • Consequences of interstitial trapping (hard, dense, corrosion-resistant) • Magnetic Properties of d-Block • Spin-Only Formula √n(n+2) • Paramagnetic vs Diamagnetic Species Examples 📍 Very Important for NEET/JEE: • Mn²⁺ and Fe³⁺ → highest magnetic moment (5 unpaired electrons) • Zn, Cd, Hg → soft metals + diamagnetic (d¹⁰ configuration) 🎯 Best For: ✔ NEET 2025 / 2026 / 2027 ✔ JEE Main & Advanced ✔ Class 12 Board Exams ✔ Revision + PYQ-based preparation 🔥 After watching this lecture, students will master: — Density trend logic — d-Block metallic bonding vs number of unpaired electrons — Catalytic behavior mechanism — Alloys & interstitial compound formation — Calculation of magnetic moment using √n(n+2) rule 💬 Doubt? Drop a comment — Rahul Sir will personally help! 👍 Like | 💬 Comment | 🔁 Share | 🔔 Subscribe 🔗 Follow for More Updates: 📢 Telegram: https://t.me/Chemclasses_with_Rahul 🌐 Website: www.chemclasseswithrahul.com 📱 Download Our App: Click Here : https://myeumu.on-app.in/app/home?org... 👉 Subscribe to *ChemClasses with Rahul* for NEET + JEE Chemistry with high-level concepts & PYQ-based learning. 👉 Subscribe to *ChemClasses with Rahul* for more high-quality NEET/JEE Chemistry lectures with full concept + PYQs. d block properties, density d block, metallic bond d block, enthalpy of atomisation d block, catalytic properties transition metals, alloy formation chemistry, interstitial compounds d block, magnetic properties d block, spin only formula, √n(n+2) magnetic moment, paramagnetic vs diamagnetic d block, transition elements class 12, d block chemistry neet, d block chemistry jee, chemclasses with rahul, neet chemistry 2025, jee chemistry 2025, transition metals trends, hard metals soft metals d block #ChemClassesWithRahul #dBlock #TransitionElements #InorganicChemistry #NEETChemistry #JEEChemistry #Class12Chemistry #MagneticMoment #CatalyticProperties #AlloyFormation #Density #HardMetals #SoftMetals