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1 bivalent element
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2 divalent element
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3 dyad
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rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 … Universalium
transition element — Chem. any element in any of the series of elements with atomic numbers 21 29, 39 47, 57 79, and 89 107, that in a given inner orbital has less than a full quota of electrons. Also called transition metal. [1920 25] * * * Any chemical element with … Universalium
carbon group element — ▪ chemical elements Introduction any of the five chemical elements that make up Group 14 (IVa) of the periodic table namely, carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead ( … Universalium
actinide element — ▪ chemical element group Introduction any of a series of 15 consecutive chemical elements in the periodic table from actinium to lawrencium (atomic numbers 89–103). As a group they are significant largely because of their radioactivity.… … Universalium
halogen element — ▪ chemical element group Introduction any of the five nonmetallic elements that constitute Group 17 (Group VIIa) of the periodic (periodic law) table. The halogen elements are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine… … Universalium
nitrogen group element — ▪ chemical elements Introduction any of the chemical elements that constitute Group Va of the periodic table (see Figure >). The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). The elements share… … Universalium
boron group element — ▪ chemical elements Introduction any of the five chemical elements constituting Group 13 (IIIa) of the periodic (periodic law) table (see Figure >). The elements are boron (B), aluminum (Al), gallium (Ga), indium (In), an … Universalium
chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… … Universalium
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