Group (periodic table)In chemistry, a group (also known as a family) is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table; the 14 f-block columns, between groups 2 and 3, are not numbered.
Group 10 elementgroup 9 ← → group 11Group 10, numbered by current IUPAC style, is the group of chemical elements in the periodic table that consists of nickel (Ni), palladium (Pd), platinum (Pt), and darmstadtium (Ds). All are d-blocktransition metals. All known isotopes of darmstadtium are radioactive with short half-lives, and are not known to occur in nature; only minute quantities have been synthesized in laboratories.
Chemical elementChemical substance not composed of simpler onesThe chemical elements ordered in the periodic table, as shown in the 32-column formatA chemical element is a species of atom defined by its number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its nucleus.
Group 9 elementGroup 9, by modern IUPAC numbering, is a group (column) of chemical elements in the d-block of the periodic table. Members of Group 9 include cobalt (Co), rhodium (Rh), iridium (Ir) and meitnerium (Mt). These elements are among the rarest of the transition metals, and as of 2025 rhodium and iridium are the only non-radioactive metals with higher prices per weight than gold.
Noble gasGroup of low-reactive, gaseous chemical elementshalogens ← → alkali metalsThe noble gases (historically the inert gases, sometimes referred to as aerogens) are the members of group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) and, in some cases, oganesson (Og).
Periodic tableTabular arrangement of the chemical elementsPeriodic table of the chemical elements showing the most or more commonly named sets of elements (in periodic tables), and a traditional dividing line between metals and nonmetals.
IronChemical element with atomic number 26 (Fe)–↑Fe↓Rumanganese ← iron → cobalt
HassiumOs↑Hs↓—bohrium ← hassium → meitnerium
RutheniumFe↑Ru↓Ostechnetium ← ruthenium → rhodium
OsmiumRu↑Os↓Hsrhenium ← osmium → iridium
Chemical Abstracts ServiceCAS (Chemical Abstracts Service) is a division of the American Chemical Society. It is a source of chemical information and is located in Columbus, Ohio, United States. Print periodicalsChemical Abstracts is a periodical index that provides numerous tools such as SciFinder as well as tagged keywords, summaries, indexes of disclosures, and structures of compounds in recently published scientific documents.
International Union of Pure and Applied ChemistryThe International Union of Pure and Applied Chemistry (IUPAC) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is a member of the International Science Council (ISC). IUPAC is registered in Zürich, Switzerland, and its administrative office, known as the "IUPAC Secretariat", is in Research Triangle Park, North Carolina, United States.*As an Amazon Associate I earn from qualifying purchases.