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For example, thorium perchlorate is very water-soluble and crystallises from acidic solutions as the tetrahydrate Th(ClO 4) 4 •4H 2 O, while thorium nitrate forms tetra- and pentahydrates, is soluble in water and alcohols, and is an important intermediate in the purification of thorium and its compounds. [25]
Thorium resources have not been estimated and assessed with a higher level of confidence, as in the case of uranium. Approximately 6 million tonnes of thorium have been estimated globally based on currently limited exploration and mainly on historical data. [4] [5] Thorium resources are found widely in over 35 countries all over the world.
Despite thorium's position in the f-block of the periodic table, it has an anomalous [Rn]6d 2 7s 2 electron configuration in the ground state, as the 5f and 6d subshells in the early actinides are very close in energy, even more so than the 4f and 5d subshells of the lanthanides: thorium's 6d subshells are lower in energy than its 5f subshells ...
Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium and any of their decay products, such as radium and radon. [1]
For each atom the subshells are given first in concise form, then with all subshells written out, followed by the number of electrons per shell. For phosphorus (element 15) as an example, the concise form is [Ne] 3s 2 3p 3 .
Monazite contains 2.5% thorium, allanite has 0.1 to 2% thorium and zircon can have up to 0.4% thorium. [2] Thorium-containing minerals occur on all continents. [3] [4] [5] Thorium is several times more abundant in Earth's crust than all isotopes of uranium combined and thorium-232 is several hundred times more abundant than uranium-235. [6]
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Grayed out electron numbers indicate subshells filled to their maximum. Bracketed noble gas symbols on the left represent inner configurations that are the same in each period. Written out, these are: He, 2, helium : 1s 2 Ne, 10, neon : 1s 2 2s 2 2p 6 Ar, 18, argon : 1s 2 2s 2 2p 6 3s 2 3p 6 Kr, 36, krypton : 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 ...