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Introduction to the 3–d block and 1st transition metal series

Abderrahmane Al jazairi 17 h 07
Pds blockd blocks and f blocks of metallic elementsp block elements
Gp1Gp2Gp3/13Gp4/14Gp5/15Gp6/16Gp7/17Gp0/18
1
1H
2He
23Li4BeThe modern Periodic Table of ElementsZSymbol, z = atomic or proton number
3d block of metallic elements: Scandium Sc to Zinc Zn		5B6C7N8O9F10Ne
311Na12Mg13Al14Si15P16S17Cl18Ar
419K20Ca21Scscandium22Tititanium23Vvanadium24Crchromium25Mnmanganese26Feiron27Cocobalt28Ninickel29Cucopper30Znzinc31Ga32Ge33As34Se35Br36Kr
537Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe
655Cs56Ba57-7172Hf73Ta74W75Re76Os77Ir78Pt79Au80Hg81Tl82Pb83Bi84Po85At86Rn
787Fr88Ra89-103104Rf105Db106Sg107Bh108Hs109Mt110Ds111Rg112Cn113Uut114Fl115Uup116Lv117Uus118Uuo

  • The elements scandium to zinc (Z = 21 to 30) are known as the 3d block of elements or 3d–block of metals because here the first of the possible d sub–shells is progressively filled (3d–block – first row of the d–blocks).
  • The transition elements are group of industrially important metals mainly due to their strong inter–atomic metallic bonding giving them generally high melting/boiling points and high tensile strength.
  • These–called 'transition metal characteristics' arise from an incomplete d sub–shell energy level but scandium and zinc are not true transition metals i.e. Ti to Cu are the real transition elements (reasoning later).
  • Note that physically, zinc is low melting and a lower tensile strength compared to the others in the 3d block.
  • Although scandium is physically typical of a transition metal e.g. high melting point and high tensile strength, chemically, scandium only forms a single and colourless triple charged ion (Sc3+). Therefore like zinc (only Zn2+), shows non of the typical characteristics of transition metal chemistry e.g. variable oxidation state, coloured complex ions, catalytic properties of the metal or ion. This is all explained in detail later.
  • Therefore probably the best definition of a transition metal is an element which forms at least one ion with an incomplete d sub–shell containing at least one electron. How this relates to variable oxidation state and coloured complex ions is elaborated further in section 10.2 and the subsequent sections on the individual metals (links below) and some of the. Zinc (Zn2+, [Ar]3d10) and scandium (Sc3+, [Ar]3d0) cannot meet this criteria.
  • The presence of the partially–filled d sub–shells of electrons gives transition elements properties which are not in general possessed by the main group elements, namely Groups 1–7 and 0, BUT, there are similarities with other metals, particularly in Groups 2, 3 and  4.


Réference: http://www.docbrown.info/page07/transition1.htm


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