Veli Pekka Pyykkö (born 12 October 1941) is a Finnish academic. He was professor of Chemistry at the

University of Helsinki The University of Helsinki ( fi, Helsingin yliopisto, sv, Helsingfors universitet, abbreviated UH) is a public research university located in Helsinki, Finland since 1829, but founded in the city of Turku (in Swedish ''Åbo'') in 1640 as the ...

. From 2009–2012, he was the chairman of the

International Academy of Quantum Molecular Science The International Academy of Quantum Molecular Science (IAQMS) is an international scientific learned society covering all applications of quantum theory to chemistry and chemical physics. It was created in Menton in 1967. The founding members wer ...

. He is known for his extension to the

periodic table The periodic table, also known as the periodic table of the (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of ch ...

of elements, known as the

Pyykkö model An extended periodic table theorises about chemical elements beyond those currently known in the periodic table and proven. , the element with the highest atomic number known is oganesson (''Z'' = 118), which completes the seventh period (row ...

Pyykkö model

After the 118 elements now known, Pekka Pyykkö predicts that the orbital shells will fill up in this order: *8s, *5g, *the first two spaces of 8p, *6f, *7d, *9s, *the first two spaces of 9p, *the rest of 8p. He also suggests that period 8 be split into three parts: *8a, containing 8s, *8b, containing the first two elements of 8p, *8c, containing 7d and the rest of 8p.

The compact version:
Pyykko periodic table 172

Pekka Pyykkö successfully predicted the possibility of a

chemical bond A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing of ...

between

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

and the

noble gas The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemi ...

xenon Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

, which is usually inert; this bond is known to occur in the

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

complex Complex commonly refers to: * Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe ** Complex system, a system composed of many components which may interact with each ...

tetraxenonogold(II) Tetraxenonogold(II), gold tetraxenide(II) or AuXe is a cationic complex with a square planar configuration of atoms. It is found in the compound AuXe(SbF) ( tetraxenonogold undecafluorodiantimonate), which exists in triclinic and tetragonal crysta ...

(). He also successfully predicted the possibility of a gold–

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

triple bond A triple bond in chemistry is a chemical bond between two atoms involving six bonding electrons instead of the usual two in a covalent single bond. Triple bonds are stronger than the equivalent single bonds or double bonds, with a bond order o ...

.Scientific American June 2013, "Cracks in the Periodic Table". p. 72.

References

1941 births Living people People involved with the periodic table Academic personnel of the University of Helsinki Finnish chemists Schrödinger Medal recipients Computational chemists {{chemist-stub