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A study in 1981 estimated that the dose from using a thorium mantle every weekend for a year would be 3–6 microsieverts (0.3–0.6 mrem), tiny in comparison to the normal annual background radiation dose of around 2.4 mSv (240 mrem), although this assumes the thorium remains intact rather than airborne. A person actually ingesting a mantle ...
Yttrium compounds are used as a catalyst for ethylene polymerization. [15] As a metal, yttrium is used on the electrodes of some high-performance spark plugs. [70] Yttrium is used in gas mantles for propane lanterns as a replacement for thorium, which is radioactive. [71]
Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely ...
In petrology and geochemistry, an incompatible element is one that is unsuitable in size and/or charge to the cation sites of the minerals in which it is included. It is defined by a partition coefficient between rock-forming minerals and melt being much smaller than 1.
The Earth's crust is one "reservoir" for measurements of abundance. A reservoir is any large body to be studied as unit, like the ocean, atmosphere, mantle or crust. Different reservoirs may have different relative amounts of each element due to different chemical or mechanical processes involved in the creation of the reservoir. [1]: 18
Thorium reacts with hydrogen to form the thorium hydrides ThH 2 and Th 4 H 15, the latter of which is superconducting below the transition temperature of 7.5–8 K; at standard temperature and pressure, it conducts electricity like a metal. [12] Thorium is the only metallic element that readily forms a hydride higher than MH 3. [31]
To understand the mantle—the largest layer of Earth’s rocky body—scientists drill deep cores out of the Earth. In May of 2023, scientists drilled the deepest core yet and recovered ...
Controversy over the exact nature of mantle convection makes the linked evolution of Earth's heat budget and the dynamics and structure of the mantle difficult to unravel. [21] There is evidence that the processes of plate tectonics were not active in the Earth before 3.2 billion years ago, and that early Earth's internal heat loss could have ...