Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Astatine


Related Topics

In the News (Mon 22 Jul 19)

  
  It's Elemental - The Element Astatine
Astatine is pronounced as AS-teh-teen or as AS-teh-ten.
Astatine was produced by Dale R. Carson, K.R. MacKenzie and Emilio Segrè by bombarding an isotope of bismuth, bismuth-209, with alpha particles that had been accelerated in a device called a cyclotron.
Small amounts of astatine exist in nature as a result of the decay of uranium and thorium, although the total amount of astatine in the earth's crust at any particular time is less than 30 grams.
education.jlab.org /itselemental/ele085.html   (0 words)

  
 Chemistry : Periodic Table : astatine : key information
Astatine is a halogen and possibly accumulates in the thyroid like iodine.
Astatine is radioactive and essentially unavailable in nature.
The bismuth target is cooled during irradiation to prevent the volatile astatine disappearing.
www.webelements.com /webelements/elements/text/At/key.html   (222 words)

  
 astatine - Encyclopedia.com
Astatine is the heaviest known halogen (Group 17 of the periodic table).
Small amounts of astatine exist in equilibrium with uranium and thorium in the earth's crust, but the total amount of astatine is probably less than 1 oz.
The discovery of astatine (first called alabamine) was announced in 1931 by Fred Allison and E. Murphy.
www.encyclopedia.com /doc/1E1-astatine.html   (188 words)

  
 ELEMENT: ASTATINE
The total amount of astatine present in the earth's crust, however, is less than 1 oz.
Astatine can be produced by bombarding bismuth with energetic alpha particles to obtain the relatively long-lived 209-211At, which can be distilled from the target by heating in air.
Astatine is said to be more metallic than iodine, and, like iodine, it probably accumulates in the thyroid gland.
www.radiochemistry.org /periodictable/elements/85.html   (240 words)

  
 Astatine (At) - Chemical properties, Health and Environmental effects
Astatine is a highly radioactive element and it is the heaviest known halogen.
Astatine is never encountered outside nuclear facilities or research laboratories.
Astatine is studied in a few nuclear research laboratories where its high radioactivity requires special handling techniques and precautions.
www.lenntech.com /Periodic-chart-elements/At-en.htm   (267 words)

  
 Chemistry : Periodic Table : astatine : historical information
Chemistry: WebElements Periodic Table: Professional Edition: Astatine: historical information
Astatine ynthesized in 1940 by Dale Corson and others at the University of California, USA, by bombarding bismuth (
If the above form fails it is probably because you are behind a "firewall" that does not allow you access to FileMaker databases (port 591).
www.webelements.com /webelements/elements/text/At/hist.html   (0 words)

  
 Astatine
Astatine is a halogen which has no stable isotopes.
Astatine has the most metallic-like properties of any of the halogens.
Astatine is highly carcinogenic: Mammary and pituitary tumors have been induced in laboratory animals by a single injection.
hyperphysics.phy-astr.gsu.edu /hbase/pertab/at.html   (78 words)

  
 Astatine | World of Chemistry
Astatine is a member of the halogen family, the elements that make up Group 17 of the periodic table.
Astatine can also be prepared artificially in particle accelerators, although no more than about a millionth of a gram has been produced by that method so far.
Astatine was one of the last of the naturally occurring elements to be discovered.
www.bookrags.com /research/astatine-woc   (259 words)

  
 Physical and Chemical Properties of Astatine - Periodic Table of the Elements
Astatine probably is capable of accumulating in the human thyroid gland.
Astatine was first synthesized by Corson, MacKenzie, and Segre at the University of California in 1940 by bombarding bismuth with alpha particles.
Astatine may be produced by bombarding bismuth with energetic alpha particles to produce At-209, At-210, and At-211.
chemistry.allinfoabout.com /periodic/at.html   (222 words)

  
 astatine. The Columbia Encyclopedia, Sixth Edition. 2001-05
Astatine is the heaviest known halogen (group VIIa of the periodic table).
Small amounts of astatine exist in equilibrium with uranium and thorium in the earth’s crust, but the total amount of astatine is probably less than 1 oz.
The discovery of astatine (first called alabamine) was announced in 1931 by Fred Allison and E. Murphy.
www.bartleby.com /65/as/astatine.html   (208 words)

  
 astatine - What is definition of the term - astatine ?   (Site not responding. Last check: )
This radioactive element occurs naturally from uranium and thorium decay and is the heaviest of the halogens.
Astatine is thought to be more metallic than iodine.
With the possible exception of francium, astatine is the rarest naturally occurring element with the total amount in Earth's crust estimated to be less than 1 oz (28 g) at any one time; this amounts to less than one teaspoon of the element.
www.linguasphere.org /dictionary/n-4638-astatine.html   (325 words)

  
 Astatine   (Site not responding. Last check: )
Astatine can be found in the atmosphere, but there is such a small amount of astatine in our atmosphere that it cannot be naturally harvested.
Astatine has been proposed in the treatment of hyperthyriodism because it accumulates in the tyroid gland in humans.
Astatine is one of the rarest elements in nature.
lakeview.esu7.org /science/at.htm   (245 words)

  
 Astatine: Free Encyclopedia Articles at Questia.com Online Library
ASTATINE as t ten, tin Gr.,=unstable, semimetallic radioactive...density unknown; valence believed to be +1, +3, +5, or +7.
Astatine is the heaviest known halogen (group VIIa of the...similar to those of iodine.
Astatine (At), formerly known as alabamine, is a radioactive element...less than 8 1 / 2 hr.
www.questia.com /library/encyclopedia/astatine.jsp?l=A&p=7   (726 words)

  
 astatine
Sence their is so little of this element in the earths crust we have'nt been able to figure out some facts about astatine.
They where able to find the amount of astatine in the earths crust by bombarding bismuth with alpha particles.They found that their is less than 1 oz of astatine in the earths crust.
Astatine is said to be even more mettalic than iodine.
www.mvschools.org /ms/academics/science/elements/jacklinastatine/jacklinastatine.html   (259 words)

  
 Astatine: Astatine   (Site not responding. Last check: )
All isotopes of astatine are radioactive and it occurs in nature only as the result of the radioactive decay of uranium.
Astatine was discovered by D R Corson, K R Mackenzie and E Segré, at The University of California, who synthesised At-211 from Bismuth-209 and alpha-particles in 1940.
Due to its instability, no visible amount of astatine is ever likely to be prepared and what little information there is about this element has been gained from studies on extremely dilute solutions (down to 2x10^-13 grams per litre), by calculation or is an informed-guess.
www.taynet.co.uk /users/astatine/local/astatine.htm   (154 words)

  
 Periodic Table Elements   (Site not responding. Last check: )
Astatine is the heaviest member of the halogen family of chemical elements.
Astatine behaves much like other halogens, particularly iodine, but has more marked metallic properties than does iodine.
Astatine is found naturally in trace quantities in uranium ores, but the total amount of it in the earth's crust is less than 1 oz.
www.mlms.logan.k12.ut.us /~mlowe/Astatine.html   (127 words)

  
 The Element Astatine
Astatine was discovered in University of California, Berkeley, USA by Dale R. Corson, K. MacKenzie, and Emilio Segre in 1940.
Check out Astatine on the Periodic Table which arranges each chemical element according to its atomic number, as based on the periodic law, so that chemical elements with similar properties are in the same column.
Our Periodic Table is simple to use - just click on the symbol for Astatine for additional information and for an instant comparison of the Atomic Weight, Melting Point, Boiling Point and Mass - G/cc with any other element.
www.periodic-table.org.uk /element-astatine.htm   (309 words)

  
 Astatine (At)
Astatine has an uranite substance that contains a small amount of astatine.
Astatine is usually in the form if an isotope.
Astatine is a halogen and possibly accumulates in the thyroid like iodine.
home.earthlink.net /~danieldorsey/periodictable04/085.htm   (67 words)

  
 85 Astatine
Astatine, francium, actinium, and protactinium are irritating to element collectors.
The problem is that astatine, francium, actinium, and protactinium are absolutely impossible to collect in any meaningful sense of the word.
But astatine, francium, actinium, and protactinium are in a whole other league of non-collectability.
www.theodoregray.com /PeriodicTable/Elements/085/index.s7.html   (716 words)

  
 Astatine   (Site not responding. Last check: )
The longest-lived isotopes, with naturally occurring uranium and thorium isotopes, and traces of 217At are equilibrium with 233U and 239Np reulting from interation of thorium and uranium with naturally produced neutrons.
Astatine can be produced by bombarding bismuth with energetic alpha particles to obtain the relatively long-lived 209-211At, which can be distilled from the target by heating in air.
The "time of flight" mass spectrometer has been used to confirm that this highly radioactive halogen behaves chemically very much like other halogens, particularly iodine.
members.tripod.com /duebills/85.html   (166 words)

  
 Nuffield Advanced Chemistry - ASTATINE (or ‘What’s that element just under iodine?)
It is assumed that astatine is entirely artificial and that nothing can be known about its properties.
Neither of these assumptions is quite true although it is estimated that there is only about 50 mg of astatine in the whole of the Earth’s crust.
Various isotopes of astatine have been produced by bombarding bismuth-209 with alpha particles.
www.chemistry-react.org /go/default/Tutorial/Tutorial_4426.html   (589 words)

  
 A Periodic Table of the Elements From Mineral Information Institute   (Site not responding. Last check: )
Description: Named from the Greek word meaning "unstable", astatine is a dark colored, metallic looking solid, somewhat similar to iodine, with chemistry that should be similar to the other halogens.
However, there is almost no natural astatine on Earth and only microscopic amounts have been produced artificially.
Obtained from: Astatine is almost non-existent on the Earth, and is found only in extremely minute quantities near uranium and thorium minerals.
www.mii.org /periodic/At.htm   (157 words)

  
 || DukeMedNews || Email
Also, Astatine's radioactive properties would enable patients to avoid isolation after treatment, enhancing their quality of life and reducing medical costs.
When bombarded by the cyclotron beam, the bismuth-coated plate efficiently generated large amounts of the astatine isotope, which could be rapidly isolated.
Zalutsky and his colleagues also have developed methods of attaching the Astatine to the antibody that can be quickly and easily carried out by a technician.
www.dukemednews.org /global/email.php?context=/news/article.php&id=573   (1452 words)

  
 astatine   (Site not responding. Last check: )
Minute quantities of 215At, 218 At, and2l9At exist in equilibrium in nature with naturally occurring uranium and thorium isotopes, and traces of 217At are equilibrium with 233U and 239Np resulting from interaction of thorium and uranium with naturally produced neutrons.
The interhalogen compounds AtI, AtBr, and AtCl are known to form, but it is not yet known if astatine forms diatomic astatine molecules.
Astatine is said to be more metallic that iodine, and, like iodine, it probably accumulates in the thyroid gland.
www.speclab.com /elements/astatine.htm   (238 words)

  
 85 Astatine
Astatine, francium, actinium, and protactinium are irritating to element collectors.
The problem is that astatine, francium, actinium, and protactinium are absolutely impossible to collect in any meaningful sense of the word.
To learn more about the set you can visit my page about element collecting for a general description and information about how to buy one, or you can see photographs of all the samples from the set displayed on my website in a periodic table layout or with bigger pictures in numerical order.
theodoregray.com /PeriodicTable/Elements/085/index.html   (716 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.