Chapter 4 / 4.3 General Properties of the Transition Elements D Block

General Properties of Transition Elements (d-Block) 😎

Most are tough, shiny metals with high tensile strength, ductility and great heat / electricity flow. :contentReference[oaicite:0]{index=0}
All (except Zn, Cd, Hg, Mn) adopt typical metallic crystal structures such as bcc, hcp or ccp. :contentReference[oaicite:1]{index=1}
They melt and boil at high temperatures; peaks appear near the middle of each series (≈ d⁵). :contentReference[oaicite:2]{index=2}
Large numbers of unpaired (n − 1)d + ns electrons lead to huge enthalpies of atomisation – the stronger the bonding, the nobler the metal. :contentReference[oaicite:3]{index=3}
Density generally climbs from Ti to Cu because radius falls while mass rises. :contentReference[oaicite:4]{index=4}

Within a series, radii shrink slightly as Z rises because added d electrons shield poorly. :contentReference[oaicite:5]{index=5}
Across 3d → 4d radii jump, but 4d ≈ 5d because 4f filling causes lanthanide contraction. (Example : Zr 160 pm, Hf 159 pm). :contentReference[oaicite:6]{index=6}

First I.E. rises only slightly Sc → Zn; second and third vary irregularly due to d–s energy shifts. :contentReference[oaicite:7]{index=7}
Half-filled (d⁵) and full (d¹⁰) shells produce noticeable “jumps” (e.g., Cr, Mn, Zn). :contentReference[oaicite:8]{index=8}
Exchange energy lowers μ for d⁵ and stabilises Mn²⁺ & Fe³⁺. :contentReference[oaicite:9]{index=9}

States differ by +1; variety peaks mid-series. Mn shows +2 → +7. :contentReference[oaicite:10]{index=10}
Early metals (Sc, Ti) lack electrons for many high states, late metals (Cu, Zn) have filled d orbitals that block very high states. :contentReference[oaicite:11]{index=11}
Highest states appear in oxides & fluorides (e.g., CrO₄²⁻, MnO₄⁻). :contentReference[oaicite:12]{index=12}

Across 3d, M²⁺/M potentials get less negative; Cu turns positive (+0.34 V) because atomisation enthalpy is low while hydration is high. :contentReference[oaicite:13]{index=13}
Mn³⁺/Mn²⁺ is strongly +ve (powerful oxidiser) due to huge third I.E.; Cr²⁺ is a good reducer. :contentReference[oaicite:14]{index=14}

Unpaired d electrons absorb visible light as they jump between split d-levels; we see the complementary hue (e.g., Ti³⁺ purple, Cu²⁺ blue). :contentReference[oaicite:15]{index=15}
Spin-only magnetic moment formula: $$\mu = \sqrt{n(n+2)}\;\text{BM}$$. :contentReference[oaicite:16]{index=16}
Moments rise with unpaired count (Mn²⁺, d⁵, ≈ 5.9 BM). Diamagnetic ions such as Zn²⁺ (d¹⁰) show 0 BM. :contentReference[oaicite:17]{index=17}

Small ionic size, high charge and empty d orbitals make them eager to form coordinate complexes like [Fe(CN)₆]⁴⁻ and [Cu(NH₃)₄]²⁺. :contentReference[oaicite:18]{index=18}
Multiple oxidation states enable catalytic cycles – V₂O₅ (Contact), Fe (Haber), Ni (hydrogenation). :contentReference[oaicite:19]{index=19}

Atoms like C, N, H slip into metal lattices forming hard, high-m.p. solids such as TiC, Fe₃H, Mn₄N. :contentReference[oaicite:20]{index=20}
Similar metal radii encourage alloying; Fe–Cr–Ni steels, brass (Cu–Zn) and bronze (Cu–Sn) showcase useful strength and durability. :contentReference[oaicite:21]{index=21}

Lanthanoid contraction and its effect on 4d / 5d size similarities. :contentReference[oaicite:22]{index=22}
Relationship between d-electron count and magnetic moment: $$\mu = \sqrt{n(n+2)}$$. :contentReference[oaicite:23]{index=23}
Trend and exceptions in M²⁺/M standard potentials (why Cu is +0.34 V). :contentReference[oaicite:24]{index=24}
Colour origin in transition-metal ions due to d–d transitions. :contentReference[oaicite:25]{index=25}
Variable oxidation states peaking at Mn, plus role of oxides/fluorides in displaying highest states. :contentReference[oaicite:26]{index=26}

🌟 Keep these points in mind, and conquering transition-metal questions will feel like metalwork magic! 🌟