Word Study
Index
: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9
[2x]
: M- M. M1 M2 M3 M< Ma Mb Mc Md Me Mf Mg Mh Mi Mk Ml Mm Mn Mo Mp Mr Ms Mt Mu Mv Mw Mx My
Table of Contents
POS
HYPHEN
CIDE DICTIONARY
mesotheca | mesothelioma | mesothelium | mesothoracic | mesothorax | mesothorium | mesotrochal | mesotron | mesotype | mesovarium | mesoxalate

mesothorium

 : 
Noun
 : 
mes=o=tho=ri=um

CIDE DICTIONARY

mesothoriumn. [NL.; meso- + thorium.].
     a radioactive isotope of radium (radium-228) with a half-life of 5.8 years. Also called mesothorium-1 or mesothorium I to distinguish it from a subsequent decay product, mesothorium II (actinium-228). It was discovered in 1907 by Otto Hahn as a decay product of thorium (produced by decay of thorium-232). Mesothorium-1 (radium-228) in turn produces actinium-228 (mesothorium-2) as the first product of its radioactive decay, and the actinium-228 in turn decays quickly (half-life of 6 hours) to thorium-228 (which is also called radiothorium; the thorium-228 has a half-life of 1.91 years, shorter than that of the radium-228). It was discovered and named before full recognition of the nature of isotopes of the elements, and was distinguished from other variants of radium by its half-life and mode of production and decay. It was also cheaper to prepare than other short-lived radium isotopes, and was thus sold commercially, for use, e.g. in making watch dials readable in the dark by painting the hands and hour marks with a self-luminous paint containing the radioactive substance; it is therefore often referred to (e.g. in regulatory legislation) as though distinct from radium. It was one of the isotopes believed responsible for radiation-induced diseases observed in industrial workers who painted radium on watch dials in the late 1950's and early 1960's. The primary isotope of radium (radium-226) has a half-life of 1620 years, and these isotopes with shorter half-lives proved difficult to isolate and study for the purpose of finding the cause of such diseases.  [Webster 1913 Suppl.]

For further exploring for "mesothorium" in Webster Dictionary Online


TIP #09: Tell your friends ... become a ministry partner ... use the NET Bible on your site. [ALL]
created in 3.72 seconds
powered by bible.org