[DOC] [TLE] Isotopes of thorium - Wikipedia [PAR] Although thorium (Th), with atomic number 90, has 6 naturally occurring isotopes, 
none of these isotopes are stable; however, one isotope, 232Th, is relatively 
stable, with a half-life of 14.05 billion years, ... 229Th is produced by the decay of 
uranium-233, and its principal use is for the production of ..... Retrieved 2010-01-
25. [DOC] [TLE] Thorium - Wikipedia [PAR] Thorium is a chemical element with symbol Th and atomic number 90. A 
radioactive actinide ... Thorium is weakly radioactive: all its known isotopes are 
unstable. .... by uranium (element 92): the isotope 232Th has a half-life of 14.05 
billion years, ... 228Th with a half-life of 1.92 years, 234Th with a half-life of 24.10 
days, and... [DOC] [TLE] Thorium-232 undergoes alpha decay and has a half-life of [PAR] A meteorite is discovered to have only 7.6% of its original thorium remaining. ... 
The mass m(t) remaining after t days from a 70 g sample of thorium-234 is given 
by the ... life of 25.5 hours, how long would it take, in days, for the sample to 
decay down to 25 mg? ... The half-life for the radioactive decay of C-14 is 5730 
years. [DOC] [TLE] Radioactivity - Health and Medical Information produced by doctors ... [PAR] Marie Curie also discovered that the element thorium is radioactive, and in 1899 
the radioactive element ... Thorium-234 emits beta particles, which are electrons. 
... which, after isolation from uranium, decays to half its original radioactive 
intensity within 25 days. ... Thorium-232, for example, has a half-life of 14 billion 
years. [DOC] [TLE] Isotopes_of_thorium : dfinition de Isotopes_of_thorium et ... [PAR] 229Th is produced by the decay of uranium-233, and its principal use is for ... 232
Th decays by alpha decay with a half-life of 1.4051010 years, over three times 
the age of the earth. ... Th-234 has a half-life of about 24.1 days, and when it 
decays, it emits a beta ... 214Th, 90, 124, 214.011500(18), 100(25) ms, , 210Ra, 
0+. [DOC] [TLE] Toxicological profile for thorium - Agency for Toxic Substances and ... [PAR] In fact, it takes about 14 billion years for half the thorium-232 to change into new 
.... Its purpose is to present levels of significant exposure for thorium based on... [DOC] [TLE] Uranium and Depleted Uranium - World Nuclear Association [PAR] Its radioactive decay provides the main source of heat inside the Earth, ... Being 
relatively soluble (in contrast to thorium), it is also found in the oceans, at an ... of 
natural uranium (25 kBq/g) is about double that of U-238 despite it consisting of 
over ..... U-238 (half-life 4.5 billion years) decays to thorium-234 (half-life 24 days)
,... [DOC] [TLE] Critique of the Matoush Uranium Project EIS (November 23 2010) [PAR] The half-life of a radioactive material is the time required for half of its ..... life of 
more than 7 days, are thorium-232 (half life 14 billion years), and radium-. [DOC] [TLE] Isotope, Radioactivity and Half-life [PAR] According to this concept, if an element is first vaporized its atoms can then be 
selectively excited and .... Thorium-234 emits beta particles, which are electrons. 
.... which, after isolation from uranium, decays to half its original radioactive 
intensity within 25 days. ... Thorium-232, for example, has a half-life of 14 billion 
years. [DOC] [TLE] Thorium-232 | Project Gutenberg Self-Publishing - eBooks | Read ... [PAR] Th, U, U, 0.7G14G ... 229Th is produced by the decay of uranium-233, 
and its principal use is for the ... 232Th decays by alpha decay with a half-life of 
1.4051010 years, over ... Th-234 has a half-life of 24.1 days, and when it decays
, it emits a beta ... 214Th, 90, 124, 214.011500(18), 100(25) ms, , 210Ra, 0

Question: For thorium-234 it's about 25 days; for thorium-232, about 14 billion years
Answer: half-life