Erbium

SYMBOL Er PERIOD 6 SERIES NAME Lanthanide ATOMIC NO 68 

ATOMIC MASS 167.259 amu VALENCE 3 OXIDATION STATE -t-3 NATURAL STATE Solid 

ORIGIN OF NAME Named for the quarry in Ytterby, Sweden, where ores and minerals of 

ISOTOPES There are 39 isotopes of erbium, six of which are stable Er-162, Er-164, Er-166, Er-167, Er-168, and Er-170. These six isotopes make up the total atomic weight (mass) of erbium, and all the other isotopes are artificially made and short-lived. Their half-lives 

Erbium is a soft, malleable metal with a silvery metallic luster that only tarnishes (oxidi2es) slightly in air. It is one of the rare-earths of the yttrium subgroup of the lanthanide series. 

Equilibrium constants are dependent upon the temperature of the system. Formation of ammonia is exothermic—heat is released as the reaction occurs N2 + 3H2 = 2NH3 + 93.7 kilojoules of energy. Therefore, cooling the reaction mixture favors the formation of even more ammonia. 

Systems may be in chemical or mechanical equilibrium, and they may also exhibit thermal equilibrium. If a hot object is placed in contact with a colder mass of the same material inside an insulated container, heat flows from the hot object into the colder object until the temperatures of the two are equal. Heat lost by the warm object is equal to the amount gained by the cold object. The amount of heat needed to raise the temperature of an object a certain amount is equal to the amount which that object would lose in cooling by the same amount. The amount of heat needed to warm or the amount lost when cooling equals the product of the specific heat (or heat capacity) of the substance, the mass, and the change in temperature. For example, if a 50-gram (1.8-ounce) piece of silver at 70°C (158°F) is placed in 50 grams (1.8 ounces) of water at 15°C (59°F), the principle of thermal equilibrium can be used to calculate the final temperature of the water and silver  

At equilibrium, if the concentrations of [HI]2 hydrogen and iodine were 1.0 mole/Liter, 

As a result of heat flowing from the silver into the water to establish a thermal equilibrium between the two, the final temperature of the silver and water is 18.1°C (64.6°F). see also Chemical Reactions Thermodynamics. 

Theodore L. Lemay, H. Eugene Bursten, Brace E. and Burdge, Julia R. (2002). Chemistry, 9th edition. Upper Saddle River, NJ Prentice-Hall. 

Data reported or calculated for the solubility constant of Er(OH)3(s) are listed in Table 8.45. The accepted data relate only to a temperature of 25 C and at zero ionic strength. No data at fixed ionic strength are retained by this review. The average of the values listed in Table 8.45 is selected as the solubility constant for Er(OH)3(s) at zero ionic strength. 

Stability constants for ErOH have been reported by Klungness and Byrne (2000) and Frolova, Kumok and Serebrennikov (1966) in NaClO media. Additionally, Ranurez-Garda et al. (2003a) and Luo et al. (1990) obtained constants in sodium chloride and sodium nitrate media, respectively. These data are listed in Table 8.46. Klungness and Byrne measured the stability of ErOH across the 

Kakihana and Maeda (1973a) and Luo et al. (1990) provided stability constants for polynuclear species of erbium. Both studies provided evidence for the formation of Er2(OH)2, with stabihty constants (log P22) —13.66 and 

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Ytterby, a village in Sweden near Vauxholm) Yttria, which is an earth containing yttrium, was discovered by Gadolin in 1794. Ytterby is the site of a quarry which yielded many unusual minerals containing rare earths and other elements. This small town, near Stockholm, bears the honor of giving names to erbium, terbium, and ytterbium as well as yttrium. 

Fig. 15. Erbium-doped fiber amplifier where x represents spHces and WDM is a wavelength division multiplexer combining the signal and pump...

Parameter Gadolinium Terbium Dysprosium Holmium Erbium ThuUmn Ytterbium Lutetium... 

Some nut trees accumulate mineral elements. Hickory nut is notable as an accumulator of aluminum compounds (30) the ash of its leaves contains up to 37.5% of AI2O2, compared with only 0.032% of aluminum oxide in the ash of the Fnglish walnut s autumn leaves. As an accumulator of rare-earth elements, hickory greatly exceeds all other plants their leaves show up to 2296 ppm of rare earths (scandium, yttrium, lanthanum, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). The amounts of rare-earth elements found in parts of the hickory nut are kernels, at 5 ppm shells, at 7 ppm and shucks, at 17 ppm. The kernel of the Bra2d nut contains large amounts of barium in an insoluble form when the nut is eaten, barium dissolves in the hydrochloric acid of the stomach. 

The same color variety is not typical with inorganic insertion/extraction materials blue is a common transmitted color. However, rare-earth diphthalocyanine complexes have been discussed, and these exhibit a wide variety of colors as a function of potential (73—75). Lutetium diphthalocyanine [12369-74-3] has been studied the most. It is an ion-insertion/extraction material that does not fit into any one of the groups herein but has been classed with the organics in reviews. Films of this complex, and also erbium diphthalocyanine [11060-87-0] have been prepared successfiiUy by vacuum sublimation and even embodied in soHd-state cells (76,77). 

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