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The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare ...
Non-ferrous metals - Metals or alloys that do not contain iron in appreciable amounts. Platinum group – Ru, Rh, Pd, Os, Ir, Pt. Post-transition metals – The metals coming after the transition metals. Many other names have been used for this set, and its borders are not agreed on.
The term rare-earth element or rare-earth metal is often used to include the stable group 3 elements Sc, Y, and Lu in addition to the 4f elements. [8] All lanthanide elements form trivalent cations, Ln 3+ , whose chemistry is largely determined by the ionic radius , which decreases steadily from lanthanum (La) to lutetium (Lu).
Late transition metals are on the right side of the d-block, from group 8 to 11 (or 12, if they are counted as transition metals). In an alternative three-way scheme, groups 3, 4, and 5 are classified as early transition metals, 6, 7, and 8 are classified as middle transition metals, and 9, 10, and 11 (and sometimes group 12) are classified as ...
[196] [197] Thus in 1864, the "Manual of Metalloids" divided all elements into either metals or metalloids, with the latter group including elements now called nonmetals. [198]: 31 Reviews of the book indicated that the term "metalloids" was still endorsed by leading authorities, [199] but there were reservations about its appropriateness.
The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties.All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.
In this system, the alkali metals, alkaline earth metals, and transition metals, as well as the lanthanides and the actinides, are special groups of the metals viewed in a broader sense. Similarly, the reactive nonmetals and the noble gases are nonmetals viewed in the broader sense.
Neodymium is a fairly common element in the Earth's crust for being a rare-earth metal. Most rare-earth metals are less abundant. Most rare-earth metals are less abundant. Neodymium is classified as a lithophile under the Goldschmidt classification , meaning that it is generally found combined with oxygen.