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The 4n decay chain of 232 Th, commonly called the "thorium series" Thorium-232 has a half-life of 14 billion years and mainly decays by alpha decay to radium-228 with a decay energy of 4.0816 MeV. [3] The decay chain follows the thorium series, which terminates at stable lead-208. The intermediates in the thorium-232 decay chain are all ...
For example, uranium-238 decays to form thorium-234. While alpha particles have a charge +2 e, this is not usually shown because a nuclear equation describes a nuclear reaction without considering the electrons – a convention that does not imply that the nuclei necessarily occur in neutral atoms.
Uranium-232 (232 U) is an isotope of uranium.It has a half-life of around 69 years and is a side product in the thorium cycle.It has been cited as an obstacle to nuclear proliferation using 233 U as the fissile material, because the intense gamma radiation emitted by 208 Tl (a daughter of 232 U, produced relatively quickly) makes the 233 U contaminated with it more difficult to handle.
Defining equation SI units Dimension Number of atoms N = Number of atoms remaining at time t. N 0 = Initial number of atoms at time t = 0 N D = Number of atoms decayed at time t = + dimensionless dimensionless Decay rate, activity of a radioisotope: A = Bq = Hz = s −1 [T] −1: Decay constant: λ
The 4n chain of thorium-232 is commonly called the "thorium series" or "thorium cascade". Beginning with naturally occurring thorium-232, this series includes the following elements: actinium, bismuth, lead, polonium, radium, radon and thallium. All are present, at least transiently, in any natural thorium-containing sample, whether metal ...
The decay scheme of a radioactive substance is a graphical presentation of all the transitions occurring in a decay, and of their relationships. Examples are shown below. It is useful to think of the decay scheme as placed in a coordinate system, where the vertical axis is energy, increasing from bottom to top, and the horizontal axis is the proton number, increasing from left to right.
A further 10 nuclides, platinum-190, samarium-147, lanthanum-138, rubidium-87, rhenium-187, lutetium-176, thorium-232, uranium-238, potassium-40, and uranium-235 have half-lives between 7.0 × 10 8 and 4.83 × 10 11 years, which means they have experienced at least 0.5% depletion since the formation of the Solar System about 4.6 × 10 9 years ...
In these, the neutrons released in the fission of plutonium are captured by thorium-232. After this radiative capture, thorium-232 becomes thorium-233, which undergoes two beta minus decays resulting in the production of the fissile isotope uranium-233. The radiative capture cross section for thorium-232 is more than three times that of uranium ...