D-block
Encyclopedia
The d-block is the portion of the periodic table
that contains the element groups 3-12. These groups correspond to the filling of the atomic d-orbital subshell, 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 metal
s 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, most define transition metals as elements with partly filled d subshells either in the neutral atom or in ions in common oxidation states. 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 metal
s. Jensen has reviewed the historical usage of the terms transition element (or metal) and d-block.
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. Group 12 elements are also in the d-block but are considered post-transition metal
s as their d-subshell
is completely filled.
Periodic table
The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...
that contains the element groups 3-12. These groups correspond to the filling of the atomic d-orbital subshell, 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 metal
Transition metal
The term transition metal has two possible meanings:*The IUPAC definition states that a transition metal is "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Group 12 elements are not transition metals in this definition.*Some...
s 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, most define transition metals as elements with partly filled d subshells either in the neutral atom or in ions in common oxidation states. 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 metal
Post-transition metal
In chemistry, the term post-transition metal is used to describe the category of metallic elements to the right of the transition elements on the periodic table...
s. Jensen has reviewed the historical usage of the terms transition element (or metal) and d-block.
In the s-block
S-block
The s-block of the periodic table of elements consists of the first two groups: the alkali metals and alkaline earth metals, plus hydrogen and helium.Except in hydrogen and helium, these electrons are very easily lost to form positive ions...
and p-block
P-block
The p-block of the periodic table of the elements consists of the last six groups minus helium . In the elemental form of the p-block elements, the highest energy electron occupies a p-orbital.-See also:...
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
Lawrencium
Lawrencium is a radioactive synthetic chemical element with the symbol Lr and atomic number 103. In the periodic table of the elements, it is a period 7 d-block element and the last element of actinide series...
are in the d-block, they are not considered transition metals but a lanthanide
Lanthanide
The lanthanide or lanthanoid series comprises the fifteen metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium...
and an actinide
Actinide
The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.The actinide series derives its name from the group 3 element actinium...
, respectively, according to IUPAC. Group 12 elements are also in the d-block but are considered post-transition metal
Post-transition metal
In chemistry, the term post-transition metal is used to describe the category of metallic elements to the right of the transition elements on the periodic table...
s as their d-subshell
Electron configuration
In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure...
is completely filled.
| Group Periodic table group In chemistry, a group is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table, including the d-block elements, but excluding the f-block elements.... → |
3 Group 3 element The group 3 elements are a group of chemical elements in the periodic table. This group, like other d-block groups, should contain four elements, but it is not agreed what elements belong in the group... |
4 Group 4 element The Group 4 elements are a group of chemical elements in the periodic table. In the modern IUPAC nomenclature, Group 4 of the periodic table contains titanium , zirconium , hafnium and rutherfordium . This group lies in the d-block of the periodic table... |
5 Group 5 element A Group 5 element is a chemical element in the fifth group in the periodic table. In the modern IUPAC nomenclature, Group 5 of the periodic table contains vanadium , niobium , tantalum and dubnium . This group lies in the d-block of the periodic table... |
6 Group 6 element A Group 6 element is one in the series of elements in group 6 in the periodic table, which consists of the transition metals chromium , molybdenum , tungsten , and seaborgium .... |
7 Group 7 element A Group 7 element is one in the series of elements in group 7 in the periodic table, which consists of manganese , technetium , rhenium , and bohrium... |
8 Group 8 element A Group 8 element is one in the series of elements in group 8 in the periodic table, which consists of the transition metals iron , ruthenium , osmium and hassium .... |
9 Group 9 element In modern IUPAC nomenclature, Group 9 of the periodic table contains the elements cobalt , rhodium , iridium , and meitnerium . These are all d-block transition metals... |
10 Group 10 element A Group 10 element is one in the series of elements in group 10 in the periodic table, which consists of the transition metals nickel , palladium , platinum , and darmstadtium .... |
11 Group 11 element A Group 11 element is one in the series of elements in group 11 in the periodic table, consisting of transition metals which are the traditional coinage metals of copper , silver , and gold... |
12 Group 12 element A group 12 element is one of the elements in group 12 in the periodic table. This includes zinc , cadmium and mercury . The further inclusion of copernicium in group 12 is supported by recent experiments on individual Cn atoms... |
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| ↓ Period Periodic table period In the periodic table of the elements, elements are arranged in a series of rows so that those with similar properties appear in vertical columns. Elements of the same period have the same number of electron shells; with each group across a period, the elements have one more proton and electron... |
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| 4 Period 4 element A period 4 element is one of the chemical elements in the fourth row of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour... |
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| 5 Period 5 element A period 5 element is one of the chemical elements in the fifth row of the periodic table of the elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour... |
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| 6 Period 6 element A period 6 element is one of the chemical elements in the sixth row of the periodic table of the elements, including the lanthanides... |
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| 7 Period 7 element A period 7 element is one of the chemical elements in the seventh row of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical... |