Définitions et usages de : D-block - Dictionnaire de anglais sensagent

This article is about a class of chemical elements. For the hip hop record label, see D-Block Records. For the hardstyle duo, see D-Block & S-te-Fan.

Periodic table: Chemical elements in the **d-block**
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

The d-block is the portion of the periodic table that contains the element groups 3-12.^[1]^[2] 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,^[1] most define transition metals as elements with partly filled d subshells either in the neutral atom or in ions in common oxidation states.^[2]^[3] This definition has now been adopted by IUPAC, and 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.^[4]

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.^[5] Group 12 elements are also in the d-block but are sometimes considered post-transition metals as their d-subshell is completely filled.^[5]

Electron shells filled in violation of Madelung's rule^[6]^[7] (red)
Period 4 after [Ar]			Period 5 after [Kr]			Period 6 after [Xe]			Period 7 after [Rn]
Scandium	21	4s² 3d¹	Yttrium	39	5s² 4d¹	Lutetium	71	6s² 4f¹⁴ 5d¹	Lawrencium	103	7s² 4f¹⁴ 7p¹?
Titanium	22	4s² 3d²	Zirconium	40	5s² 4d²	Hafnium	72	6s² 4f¹⁴ 5d²	Rutherfordium	104	7s² 4f¹⁴ 6d²?
Vanadium	23	4s² 3d³	Niobium	41	5s¹ 4d⁴	Tantalum	73	6s² 4f¹⁴ 5d³	Dubnium	105	(unknown)
Chromium	24	4s¹ 3d⁵	Molybdenum	42	5s¹ 4d⁵	Tungsten	74	6s² 4f¹⁴ 5d⁴	Seaborgium	106	(unknown)
Manganese	25	4s² 3d⁵	Technetium	43	5s² 4d⁵	Rhenium	75	6s² 4f¹⁴ 5d⁵	Bohrium	107	(unknown)
Iron	26	4s² 3d⁶	Ruthenium	44	5s¹ 4d⁷	Osmium	76	6s² 4f¹⁴ 5d⁶	Hassium	108	(unknown)
Cobalt	27	4s² 3d⁷	Rhodium	45	5s¹ 4d⁸	Iridium	77	6s² 4f¹⁴ 5d⁷	Meitnerium	109	(unknown)
Nickel *^[8]	28	4s² 3d⁸ or 4s¹ 3d⁹	Palladium	46	4d¹⁰	Platinum	78	6s¹ 4f¹⁴ 5d⁹	Darmstadtium	110	(unknown)
Copper	29	4s¹ 3d¹⁰	Silver	47	5s¹4d¹⁰	Gold	79	6s¹ 4f¹⁴ 5d¹⁰	Roentgenium	111	(unknown)
Zinc	30	4s² 3d¹⁰	Cadmium	48	5s² 4d¹⁰	Mercury	80	6s² 4f¹⁴ 5d¹⁰	Copernicium	112	(unknown)

References

^ ^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)
^ 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 0-19-530573-6. http://books.google.com/?id=SNRdGWCGt1UC&pg=PA239.

Periodic tables

Layouts and properties	Standard Compact Large table Inline f-block Vertical Text only Metals and nonmetals Blocks Maximum valences Extension beyond the 7th period Pyykkö model Large extended table Large wide table Electron configurations Electronegativities Allen scale electronegativities Alternatives Janet table compact Chemical Galaxy Crystal structure Goldschmidt classification Atomic weights Dietary elements Vertical Wide large Nutritional elements Metalloid border Electron affinities Transuranium elements

List of elements by	Symbol Abundance (in humans) Nuclear stability Atomic properties Production

Data pages	Electron configurations Densities Electron affinities Melting points Boiling points Critical points Heats of fusion Heats of vaporization Heat capacities Vapor pressures Pauling electronegativities Ionization energies Atomic radii Electrical resistivities Thermal conductivities Thermal expansion coefficients Speeds of sound Elastic properties Hardnesses Abundances Oxidation states

Groups	1 (Alkali metals) 2 (Alkaline earth metals) 3 4 5 6 7 8 9 10 11 12 13 (Boron group) 14 (Carbon group) 15 (Pnictogens) 16 (Chalcogens) 17 (Halogens) 18 (Noble gases)

Other element categories	Periods Metals Transition metals Metalloids Nonmetals Lanthanides Actinides Superactinides Rare earth elements Platinum group metals (PGMs) Post-transition metals Refractory metals

Blocks	s-block p-block d-block f-block g-block

Periods	1 2 3 4 5 6 7 8

History	Element disoveries History of the periodic table Name etymology places scientists

See also	Dmitri Mendeleev IUPAC nomenclature Systematic element name Groups of elements Trivial name Chemical elements in East Asian languages

Book:Periodic table Category:Periodic table Portal:Chemistry

Significations et usages de D-block

Définition

d-block

See also

References