Search results
v. t. e. In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. The lanthanide and actinide elements (the f-block) are called inner transition metals and are sometimes considered to be ...
Data element definition. In metadata, a data element definition is a human readable phrase or sentence associated with a data element within a data dictionary that describes the meaning or semantics of a data element. Data element definitions are critical for external users of any data system. Good definitions can dramatically ease the process ...
Primitive element (finite field), an element that generates the multiplicative group of a finite field. Primitive element (lattice), an element in a lattice that is not a positive integer multiple of another element in the lattice. Primitive element (coalgebra), an element X on which the comultiplication Δ has the value Δ ( X) = X ⊗1 + 1⊗ X.
Group 10 elements are observed in oxidation states of +1 to +4.[2] The +2 oxidation state is common for nickel and palladium, while +2 and +4 are common for platinum. Oxidation states of -2 and -1 have also been observed for nickel[3][4] and platinum,[5] and an oxidation state of +5 has been observed for palladium[6] and platinum.[7]
A period on the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor. Arranged this way, elements in the same group (column) have similar chemical and physical properties, reflecting the periodic law.
In some cases, the average oxidation state of an element is a fraction, such as 8 / 3 for iron in magnetite Fe 3 O 4 . The highest known oxidation state is reported to be +9, displayed by iridium in the tetroxoiridium(IX) cation (IrO + 4). It is predicted that even a +10 oxidation state may be achieved by platinum in tetroxoplatinum(X), PtO 2+ 4.
The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure, though not far above room temperature the same becomes true of groups 1 and 15, assuming white phosphorus is taken as the standard state. All of the halogens form acids when bonded to hydrogen.
