Rb-and-Sr-are-relatively-mobile-alkaline-elements

[permalink] [id link]

+ −

Page "Rubidium-strontium dating" ¶ 16

from Wikipedia

Promote Demote Fragment Fix

« More previous Okay Cancel More next »

Some Related Sentences

Rb and Sr

The rubidium-strontium dating method is a radiometric dating technique used by scientists to determine the age of rocks and minerals from the quantities they contain of specific isotopes of rubidium ( 87 Rb ) and strontium ( 87 Sr, 86 Sr.

The utility of the rubidium-strontium isotope system results from the fact that 87 Rb ( one of two naturally occurring isotopes of rubidium ) decays to 87 Sr with a halflife of 48. 8 billion years.

Different minerals in a given geologic setting can acquire distinctly different ratios of radiogenic strontium-87 to naturally occurring strontium-86 ( 87 Sr / 86 Sr ) through time ; and their age can be calculated by measuring the 87 Sr / 86 Sr in a mass spectrometer, knowing the amount of 87 Sr present when the rock or mineral formed, and calculating the amount of 87 Rb from a measurement of the Rb present and knowledge of the 85 Rb / 87 Rb weight ratio.

However, because Rb substitutes for K in minerals and these minerals have different K / Ca ratios, the minerals will have had different Rb / Sr ratios.

Rb and are

The alkali metals are lithium ( Li ), sodium ( Na ), potassium ( K ), rubidium ( Rb ), caesium ( Cs ), and francium ( Fr ).

then there are elements x and y in R such that ax + by = d. The reason: the ideal Ra + Rb is principal and indeed is equal to Rd.

The processing of oceanic crust, lithosphere, and sediment through a subduction zone decouples the water soluble trace elements ( e. g., K, Rb, Th ) from the immobile trace elements ( e. g., Ti, Nb, Ta ), concentrating the immobile elements in the oceanic slab ( the water soluble elements are added to the crust in island arc volcanoes ).

The subducting slab is depleted in these water-mobile elements ( e. g., K, Rb, Th, Pb ) and thus relatively enriched in elements that are not water-mobile ( e. g., Ti, Nb, Ta ) compared to both mid-ocean ridge and island arc basalts.

# Elements which are similar as regards to their chemical properties have atomic weights which are either of nearly the same value ( e. g., Pt, Ir, Os ) or which increase regularly ( e. g., K, Rb, Cs ).

Geochemically, carbonatites are dominated by incompatible elements ( Ba, Cs, Rb ) and depletions in compatible elements ( Hf, Zr, Ti ).

The alkali metals are the series of elements in Group 1 of the periodic table ( excluding hydrogen in all but one rare circumstance ): lithium ( Li ), sodium ( Na ), potassium ( K ), rubidium ( Rb ), caesium ( Cs ), and francium ( Fr ).

It is so named because defects in Rb are linked to retinoblastoma.

For instance, individuals that are heterozygous for p53 mutations are often victims of Li-Fraumeni syndrome, and that are heterozygous for Rb mutations develop retinoblastoma.

Thus, there are two sources of 87 Sr in any material: that formed during primordial nucleo-synthesis along with 84 Sr, 86 Sr and 88 Sr, as well as that formed by radioactive decay of 87 Rb.

Other than 87 Rb, the longest-lived radioisotopes are 83 Rb with a half-life of 86. 2 days, 84 Rb with a half-life of 33. 1 days and 86 Rb with a half-life of 18. 642 days.

Rb and elements

Intermediate elements have their ( or their oxides ) boiling points close to the solidification temperature of the particles ( Rb, Cs, Mo, Ru, Rh, Tc, Sb, Te ).

This favors producing a melt rich in large-ion lithophile elements ( LILE ) such as K, Ba, Rb, Cs, Sr.

Boninites with 10-18 % MgO tend to have higher large-ion lithophile elements ( LILE ) ( Ba, Rb, Sr ) than komatiites.

Rb and such

The best performance ( in terms of thrust efficiency and power-to-thrust ratio ) can be obtained using high atomic weight alkali metals, such as cesium and rubidium ( 133 amu for Cs, 85. 5 amu for Rb ).

An even more exotic type of perovskite is represented by the mixed oxide-aurides of Cs and Rb, such as Cs 3 AuO, which contain large alkali cations in the traditional " anion " sites, bonded to O 2 − and Au − anions.

Rb and by

The first instrumental analysis was flame emissive spectrometry developed by Robert Bunsen and Gustav Kirchhoff who discovered rubidium ( Rb ) and caesium ( Cs ) in 1860.

If the initial amount of Sr is known or can be extrapolated, the age can be determined by measurement of the Rb and Sr concentrations and the 87 Sr / 86 Sr ratio.

Interestingly, two forms of Rb 2 C 2 O 4 have been structurally characterized by single-crystal, X-ray diffraction: one contains a planar and the other a staggered oxalate.

Only 87 Sr is radiogenic ; it is produced by decay from the radioactive alkali metal 87 Rb, which has a half-life of 4. 88 × 10 10 years.

87 Rb has been used extensively in dating rocks ; 87 Rb decays to stable strontium-87 by emission of a negative beta particle.

Rb and hydrothermal

One of the major drawbacks ( and, conversely, the most important use ) of utilizing Rb and Sr to derive a radiometric date is their relative mobility, especially in hydrothermal fluids.

Rb and fluids

Conversely, these fluids may metasomatically alter a rock, introducing new Rb and Sr into the rock ( generally during potassic alteration or calcic ( albitisation ) alteration.

Rb and during

In addition, Rb is a highly incompatible element that, during fractional crystallization of the mantle, stays in the magmatic melt rather than becoming part of mantle minerals.

Rb and .

This level likewise has a fast, non-radiative decay Rb into the ground state.

Rubidium ( ) is a chemical element with the symbol Rb and atomic number 37.

Rubidium has only one stable isotope, 85 Rb, with the isotope 87 Rb, which composes almost 28 % of naturally occurring rubidium, being slightly radioactive with a half-life of 49 billion years — more than three times longer than the estimated age of the universe.

During fractional crystallization, Sr tends to become concentrated in plagioclase, leaving Rb in the liquid phase.

Hence, the Rb / Sr ratio in residual magma may increase over time, resulting in rocks with increasing Rb / Sr ratios with increasing differentiation.

Typically, Rb / Sr increases in the order plagioclase, hornblende, K-feldspar, biotite, muscovite.

Each of these minerals has a different initial rubidium / strontium ratio dependent on their potassium content, the concentration of Rb and K in the melt and the temperature at which the minerals formed.

The ideal scenario according to Bowen's reaction series would see a granite melt begin crystallizing a cumulate assemblage of plagioclase and hornblende ( i. e. ; tonalite or diorite ), which is low in K ( and hence Rb ) but high in Sr ( as this substitutes for Ca ), which proportionally enriches the melt in K and Rb.

Sr and are

Brighter atoms are Strontium | Sr and darker ones are Ti.

He was therefore mentioned in a stanza of the Oliver Wendell Holmes, Sr. poem, " At the Saturday Club ," where the author dreams he sees some of his friends who are no longer:

These three phases are Bi-2201, Bi-2212 and Bi-2223, having transition temperatures of 20, 85 and 110 K, respectively, where the numbering system represent number of atoms for Bi, Sr, Ca and Cu respectively .< ref >

" Sozzini's grandson Andrzej Wiszowaty Sr. in 1665-1668 published Bibliotheca Fratrum Polonorum quos Unitarios vocant ( Library of the Polish Brethren who are called Unitarians 4 vols.

Initial 87 Sr / 86 Sr ratios are a useful tool in archaeology, forensics and paleontology because the 87 Sr / 86 Sr of a skeleton, sea shell or indeed a clay artefact is directly comparable to the source rocks upon which it was formed or upon which the organism lived.

The alkaline earth metals are beryllium ( Be ), magnesium ( Mg ), calcium ( Ca ), strontium ( Sr ), barium ( Ba ), and radium ( Ra ).

Brighter atoms are Strontium | Sr and darker ones are Titanium | Ti.

Screen names are also used to create a more marketable name, as in the case of Creighton Tull Chaney, who adopted the pseudonym Lon Chaney, Jr., a reference to his famous father Lon Chaney, Sr. On the converse, Nicolas Cage adopted this stage name instead of his real name, Nicolas Kim Coppola, in order to conceal the appearance of nepotism as the nephew of famous director Francis Ford Coppola.

The only major M-G-M stars missing from the revue are Greta Garbo, Ramón Novarro, and Lon Chaney, Sr., although Chaney is referred to by name in one of the songs performed.

Buddenbrooks ( 1901 ), by Thomas Mann ( 1875 – 1955 ), chronicles the moral decay of a rich family through its declines, material and spiritual, in the course of four generations, beginning with the patriarch Johann Buddenbrook Sr. and his son, Johann Buddenbrook Jr., who are typically successful German businessmen ; each is a reasonable man of solid character.

In nineteenth century France, the radical theories of Louis Pasteur ( Paul Muni ) are dismissed by most doctors, particularly his most vocal critic, Dr. Charbonnet ( Fritz Leiber, Sr .).

The Waltons are played by Tyrone Power, Sr. and Helen Riaume who at the time were real life husband and wife.

* Calcium sulfide with strontium sulfide with bismuth as activator, ( Ca, Sr ) S: Bi, yields blue light with glow times up to 12 hours, red and orange are modifications of the zinc sulfide formula.

Other elected officials in Somerset County are Sheriff Frank J. Provenzano, Sr., County Clerk Brett A. Radi and Surrogate Frank Bruno.

, members of the Burlington County Board of Chosen Freeholders ( with their term end dates and committee chairmanships listed in parentheses ) are Freeholder Director William Whelan ( 2011 ; Finance ), Deputy Freeholder Director James A. Dunkins ( 2011 ; Health ), Samuel L. Fiocchi, Sr. ( 2013 ; Public Works ), Jane Jannarone ( 2011 ; Public Affairs, Cultural & History ), Carl W. Kirstein ( 2013 ; Public Property & Personnel ) and Thomas Sheppard ( 2012 ; Agriculture ).

Among our members now living are Mr. Douglas Inglis of Worcester, Mass., Mr. Raymand Cave of Watertown Mass., Dr. Stanton Burgess of Boston Mass., Mr. George Murry of Quincy Mass., Mr. Ronald Cragg, last known address in Pennsylvania, James Grearson Sr. of this city, Mr. William Cheeney of Northfield, Vt. Other members of our troups I now recall their names ere Carl and Earl Burgess, brothers of the above mentioned doctor.

The current council leaders are Arnold Beach Sr. and Gregg Henry.

0.367 seconds.