D-block Information
The d-block is the portion of the periodic table that contains the element groups 3-12.[4][5] These groups correspond to the filling of the atomic d-orbital subshell of the second outermost shell (inside an outermost shell only containing 1 or 2 s-orbital electrons) with electron configurations ranging from s2d1 (Group 3) to s2d10 (Group 12). There are some irregularities in the sequence; for example Cr is s1d5 (not s2d4) and the Group 11 metals are s1d10 (not s2d9), so that the d-subshell is actually complete at Group 11.
The d-block elements are often also known as transition metals or transition elements. However the exact limits of the transition metal region are usually not considered to be identical to the d-block. Although some authors do identify the entire d-block as transition metals,[4] most define transition metals as elements with partly filled d subshells either in the neutral atom or in ions in common oxidation states.[5][6] This definition has now been adopted by IUPAC corresponds to including only Groups 3-11 as transition metals. Group 12 metals lack the characteristic chemical and physical properties associated with incomplete d subshells and are considered post-transition metals. Jensen has reviewed the historical usage of the terms transition element (or metal) and d-block.[7]
In the s-block and p-block of the periodic table, similar properties across the periods are generally not observed: the most important similarities tend to be vertical, down groups. However the d-block is notable in that horizontal similarities across the periods do become important.
Although lutetium and lawrencium are in the d-block, they are not considered transition metals but a lanthanide and an actinide, respectively, according to IUPAC.[8] Group 12 elements are also in the d-block but are sometimes considered post-transition metals as their d-subshell is completely filled.[8]
| Group → | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|
| ↓ Period | ||||||||||
| 4 | 21 Sc | 22 Ti | 23 V | 24 Cr | 25 Mn | 26 Fe | 27 Co | 28 Ni | 29 Cu | 30 Zn |
| 5 | 39 Y | 40 Zr | 41 Nb | 42 Mo | 43 Tc | 44 Ru | 45 Rh | 46 Pd | 47 Ag | 48 Cd |
| 6 | 71 Lu | 72 Hf | 73 Ta | 74 W | 75 Re | 76 Os | 77 Ir | 78 Pt | 79 Au | 80 Hg |
| 7 | 103 Lr | 104 Rf | 105 Db | 106 Sg | 107 Bh | 108 Hs | 109 Mt | 110 Ds | 111 Rg | 112 Cn |
See also
References
- ^ G.L. Miessler and D.A. Tarr, "Inorganic Chemistry" (2nd ed., Prentice-Hall 1999) p.38
- ^ See references in the article: electron configurations of the elements (data page)
- ^ Scerri, Eric R. (2007). The periodic table: its story and its significance. Oxford University Press. pp. 239–240. ISBN 0195305736. http://books.google.com/?id=SNRdGWCGt1UC&pg=PA239.
- ^ a b R.H. Petrucci, W.S. Harwood and F.G. Herring “General Chemistry” (8th ed, Prentice-Hall 2002), p.341-2
- ^ a b C.E. Housecroft and A.G. Sharpe “Inorganic Chemistry” (2nd ed, Pearson Prentice-Hall 2005), p..20-21
- ^ F.A. Cotton and G. Wilkinson “Advanced Inorganic Chemistry” (5th ed, John Wiley 1988) p.625
- ^ Jensen, William B. (2003). "The Place of Zinc, Cadmium, and Mercury in the Periodic Table". Journal of Chemical Education 80 (8): 952–961. Bibcode 2003JChEd..80..952J. doi:10.1021/ed080p952. http://www.uv.es/~borrasj/ingenieria_web/temas/tema_1/lecturas_comp/p952.pdf.
- ^ a b IUPAC Provisional Recommendations for the Nomenclature of Inorganic Chemistry (2004) (online draft of an updated version of the "Red Book" IR 3-6)
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