Main - group element - wikipedia Main - group element The periodic table of the chemical elements. The columns represent the groups. Groups 1, 2 and 13 to 18 constitute the main group. Sometimes groups 3 and 12, as well as the lanthanides and actinides ( the two rows at the bottom ), are also included in the main group. In chemistry and atomic physics, the main group is the group of elements whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the periodic table of the elements. The main group includes the elements ( except hydrogen, which is sometimes not included ) in groups 1 and 2 ( s - block ), and groups 13 to 18 ( p - block ). The s - block elements are primarily characterised by one main oxidation state, and the p - block elements, when they have multiple oxidation states, often have common oxidation states separated by two units. Group 12 elements are often considered to be transition metals ; however, zinc ( Zn ), cadmium ( Cd ), and mercury ( Hg ) share some properties of both groups, and many scientists believe they should be included in the main group. Occasionally, even the group 3 elements as well as the lanthanides and actinides have been included, because especially the group 3 elements and lanthanides are electropositive elements with only one main oxidation state like the group 1 and 2 elements. The position of the actinides is more questionable, but the most common and stable of them, thorium ( Th ) and uranium ( U ), are similar to main - group elements as thorium is an electropositive element with only one main oxidation state ( + 4 ), and uranium has two main ones separated by two oxidation units ( + 4 and + 6 ). In older nomenclature the main - group elements are groups IA and IIA, and groups IIIB to 0 ( CAS groups IIIA to VIIIA ). Group 12 is labelled as group IIB in both systems. Group 3 is labelled as group IIIA in the older nomenclature ( CAS group IIIB ). Main - group elements ( with some of the lighter transition metals ) are the most abundant elements on Earth, in the Solar System, and in the Universe. They are sometimes also called the representative elements. References Jump up ^ `` Nomenclature of Inorganic Chemistry ''. International Union of Pure and Applied Chemistry. Retrieved 27 September 2011. Jump up ^ Jensen, William B. ( 2003 ). `` The Place of Zinc, Cadmium, and Mercury in the Periodic Table '' ( PDF ). Journal of Chemical Education. 80 ( 8 ) : 952. Bibcode : 2003JChEd... 80... 952J. doi : 10.1021 / ed080p952. Jump up ^ King, R. Bruce ( 1995 ). Inorganic Chemistry of Main Group Elements. Wiley - VCH. ISBN 0 - 471 - 18602 - 3. Bibliography Ralf Steudel, `` Chemie der Nichtmetalle '' ( Chemistry of the nonmetals ), 2nd Edition. Walter deGruyter, Berlin 1998. ISBN 3 - 11 - 012322 - 3 Periodic table Periodic table forms Standard 18 - column 18 - column, large cells 32 - column, large cells Alternative Alternatives Chemical Galaxy Janet 's left step table Extended Extension beyond the 7th period Fricke model large cells Pyykkö model Sets of elements By periodic table structure Groups 1 ( Alkali metals ) 2 ( Alkaline earth metals ) 5 6 7 8 9 10 11 12 13 14 15 ( Pnictogens ) 16 ( Chalcogens ) 17 ( Halogens ) 18 ( Noble gases ) Periods 5 6 7 8 + Aufbau Fricke Pyykkö Blocks s - block p - block d - block f - block g - block Aufbau principle By metallicity Metals Alkali metals Alkaline earth metals Lanthanides Actinides Superactinides Transition metals Post-transition metals Metalloids Lists of metalloids by source Dividing line Nonmetals Polyatomic nonmetals Diatomic nonmetals Noble gases Other sets Nutritional elements Platinum - group metals ( PGM ) Rare - earth elements Refractory metals Precious metals Coinage metals Noble metal Heavy metals Native metals Transuranium elements Transactinide elements Major actinides Minor actinides Elements Lists By : Abundance ( in humans ) Atomic properties Nuclear stability Production Symbol Properties Atomic weight Crystal structure Electron affinity Electron configuration Electronegativity Allen Pauling Goldschmidt classification Maximum valence Data pages Abundance Atomic radius Boiling point Critical point Density Elasticity Electrical resistivity Electron affinity Electron configuration Electronegativity Hardness Heat capacity Heat of fusion Heat of vaporization Ionization energy Melting point Oxidation state Speed of sound Thermal conductivity Thermal expansion coefficient Vapor pressure History Element discoveries Mendeleev 's predictions Naming Etymology controversies places scientists in East Asia See also IUPAC nomenclature systematic element name Trivial name Dmitri Mendeleev Book Chemistry Portal Retrieved from `` https://en.wikipedia.org/w/index.php?title=Main-group_element&oldid=815964547 '' Categories : Sets of chemical elements Hidden categories : Use dmy dates from July 2012 Talk About Wikipedia Català Dansk Deutsch Español Français 한국어 Bahasa Indonesia Magyar Nederlands 日本 語 Plattdüütsch Português ไทย 中文 6 more Edit links This page was last edited on 18 December 2017, at 10 : 31. 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Question: what category of elements is the most common in the periodic table
Answer: Main-group