Ytterbium

Ytterbium is a chemical element with symbol Yb and atomic number 70. It is the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. However, like the other lanthanides, its most common oxidation state is +3, seen in its oxide, halides and other compounds. In aqueous solution, like compounds of other late lanthanides, soluble ytterbium compounds form complexes with nine water molecules. Because of its closed-shell electron configuration, its density and melting and boiling points differ from those of the other lanthanides.

In 1878, the Swiss chemist Jean Charles Galissard de Marignac separated in the rare earth "erbia" another independent component, which he called "ytterbia", for Ytterby, the village in Sweden near where he found the new component of erbium. He suspected that ytterbia was a compound of a new element that he called "ytterbium" (in total, four elements were named after the village, the others being yttrium, terbium and erbium). In 1907, the new earth "lutecia" was separated from ytterbia, from which the element "lutecium" (now lutetium) was extracted by Georges Urbain, Carl Auer von Welsbach, and Charles James. After some discussion, Marignac's name "ytterbium" was retained. A relatively pure sample of the metal was obtained only in 1953. At present, ytterbium is mainly used as a dopant of stainless steel or active laser media, and less often as a gamma ray source.

Ytterbium is present in earth's crust at concentrations around 3 parts per million (by mass). There are no Yb-based minerals because the element is chemically very similar to the other lanthanide elements. Instead, Yb is extracted from ores containing other rare-earth elements, most commonly monazite, euxenite, and xenotime. The ytterbium concentration is low, because the element is inherently less common than the lighter lanthanides found with it.

Thirty-five isotopes of Yb have been observed, along with 12 isomers. A total of 91 isotopes are predicted to be possible. Isotopes ¹⁷⁷Yb and heavier all decay by beta emission. (Very heavy isotopes decay by beta + neutrons emission.) Half-lives decline from 1.9 hr at ¹⁷⁷Yb to roughly 0.001 sec at the neutron dripline. Isotopes ¹⁶⁷Yb and lighter decay by positive charge emission. All of these which have been observed have a positive beta decay (positron emission or electron capture). In some cases, proton emission is observed, and ¹⁴⁰Yb, the lightest predicted isotope, is expected to decay mainly by proton emission. Isotopes in the range ¹⁵⁸Yb to ¹⁵³Yb also have an alpha-decay branch which occurs due to destabilization above the closed shell at N = 82. Of the light isotopes of Yb, all but ¹⁶⁶Yb have half-lives under 1 hour. (Half-life of ¹⁶⁶Yb = 56.7 hr.)

Peak stability occurs in the band ¹⁷⁶Yb to ¹⁶⁸Yb. Seven of these isotopes are stable. The most abundant isotopes ¹⁷⁴Yb (number fraction 0.32), ¹⁷²Yb (0.22), ¹⁷³Yb (0.16), and ¹⁷¹Yb (0.14) can all form either by infrequent capture of neutrons in highly-evolved stars (s process) or by rapid capture / beta decay during supernovae or neutron star mergers (r process). ¹⁷⁶Yb, by contrast forms only via the r process, while ¹⁷⁰Yb forms only via the s process. Relative abundance of the former (0.13) and the latter (0.03) indicate that the r process is more important than the s process for producing Yb. The lightest stable isotope, ¹⁶⁸Yb, is rare (0.001) because it cannot be produced via neutron capture. Gamma capture followed by neutron emission is the most likely synthesis route for this isotope.

9-Period Periodic Table of Elements
1	1 H																																																																	2 He
2	3 Li	4 Be																																																																	5 B	6 C	7 N	8 O	9 F	10 Ne
3	11 Na	12 Mg																																																																	13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
4	19 K	20 Ca																																																																	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
5	37 Rb	38 Sr																																																																	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
6	55 Cs	56 Ba																																																					57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
7	87 Fr	88 Ra																																																					89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Nh	114 Fl	115 Mc	116 Lv	117 Ts	118 Og
8	119 Uue	120 Ubn																															121 Ubu	122 Ubb	123 Ubt	124 Ubq	125 Ubp	126 Ubh	127 Ubs	128 Ubo	129 Ube	130 Utn	131 Utu	132 Utb	133 Utt	134 Utq	135 Utp	136 Uth	137 Uts	138 Uto	139 Ute	140 Uqn	141 Uqu	142 Uqb	143 Uqt	144 Uqq	145 Uqp	146 Uqh	147 Uqs	148 Uqo	149 Uqe	150 Upn	151 Upu	152 Upb	153 Upt	154 Upq	155 Upp	156 Uph	157 Ups	158 Upo	159 Upe	160 Uhn	161 Uhu	162 Uhb	163 Uht	164 Uhq	165 Uhp	166 Uhh	167 Uhs	168 Uho	169 Uhe	170 Usn	171 Usu	172 Usb
9	173 Ust	174 Usq
Alkali metal Alkaline earth metal Lanthanide Actinide Superactinide Transition metal Post-transition metal Metalloid Other nonmetal Halogen Noble gas predicted predicted predicted predicted predicted predicted predicted predicted predicted