Yttrium atomic weight

Yorke, lltblnm orthoailicatc, 673 Yttrium, atomic weight of, 62... 

Yttrium is always found with the rare-earth elements, and in some ways it resembles them. Although it is sometimes classified as a rare-earth element, it is listed in the periodic table as the first element in the second row (period 5) of the transition metals. It is thus also classified as the lightest in atomic weight of all the rare-earths. (Note Yttrium is located in the periodic table just above the element lanthanum (group 3), which begins the lanthanide rare-earth series. 

Oxides of the type RjO arc formed by all rare earth elements, by the ignition of the hydroxide, nitrate, sulfate, carbonate, or oxalate. In general the basicity decreases with increase of atomic weight, though yttrium and scandium are exceptions to the rule. The basicity of lanthanum approaches that of the alkaline earths, while scandium is about as basic as aluminium. 

Double nitrates of the cerium group are easily crystallized. Th stability decreases gradually with rise of atomic weight of the metal, a in the yttrium group crystalline double nitrates do not form. Cfc sequently, the use of the double nitrates in fractionation is limited to I cerium group. 

The structure of yttrium approaches even more closely that of the rare earth metals, for like these latter its M shell is complete, and in its chemical properties it so closely resembles those with the higher atomic weights that elements 63 to 71 are frequently classed as belonging to the yttrium group. We shall observe this classification in the present section. 

In 1901 Hofmann and Prandtl claimed that a specimen of zirconia extracted from euxenite contained the oxide of a metal of high atomic weight. Euxenite is a very complex niobotantalate of uranium, yttrium and the rare earth metals in which Nilson h d found scandia in 1879 (p. 172). But Hauser and Wirthf could not confirm the presence of a new element. 

It thus appears that seven little studied elements remained outside of the table This septuplet of homeless elements consisted of indium (In), thorium (Th) and the five rare earths—erbium (Er), yttrium (Yt), cerium (Ce), lanthanum (La), and didymium (Di). Question marks and wrong atomic weights reigned in the last rows of Mendeleev s system, and a new place had to be found for the homeless septuplet We will call this problematic accommodation issue the rare-earth crisis. 

As a rule, yttrium (Y) is included in the rare earth group. While its electron configuration differs from that of lanthanides, the volume contraction of the latter with increase in their atomic weight justifies inclusion of Y, the atoms of which are very similar in density and volume to those of the lanthanide series. This similarity is also reflected in nature, where REE and Y coexist in many minerals. In fact, rare earths are frequently referred to as yttria earths . 

Roscoe discovered tungsten pentachloride and pentabromide, uranium pentachloride,2 and niobium trichloride (which he found gave NbOClg and CO when heated in COg). He determined the vapour densities of PbClg and TlCl, showed that Delafontaine s supposed new rare-earth metal philippium is a mixture of yttrium and terbium, and redetermined the atomic weight of carbon (C = 12 002). Roscoe published several papers and a book on spectrum analysis. 

As previously mentioned, Mendeleev was not, in fact, the first to predict unknown elements. William Odling,John Newlands, and Julius Lothar Meyer all did so before him. E.g., Newlands left spaces for yttrium, indium, and germanium. For germanium, he predicted an atomic weight of 73, which compares very favorably with the current value of 72.59. 

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