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Scandium compounds are compounds containing the element scandium. The chemistry of scandium is almost completely dominated by the trivalent ion, Sc 3+ , due to its electron configuration , [Ar] 3d 1 4s 2 .
The abundance of elements in Earth's crust for group 3 is quite low—all the elements in the group are uncommon, the most abundant being yttrium with abundance of approximately 30 parts per million (ppm); the abundance of scandium is 16 ppm, while that of lutetium is about 0.5 ppm. For comparison, the abundance of copper is 50 ppm, that of ...
In each case, scandium is a byproduct of the extraction of other elements and is sold as scandium oxide. [29] [30] [31] To produce metallic scandium, the oxide is converted to scandium fluoride and then reduced with metallic calcium. [32] Sc 2 O 3 + 6HF → 2ScF 3 + 3H 2 O; 2ScF 3 + 3Ca → 3CaF 2 + 2Sc
The molecular orbitals are labelled according to their symmetry, [e] rather than the atomic orbital labels used for atoms and monatomic ions; hence, the electron configuration of the dioxygen molecule, O 2, is written 1σ g 2 1σ u 2 2σ g 2 2σ u 2 3σ g 2 1π u 4 1π g 2, [39] [40] or equivalently 1σ g 2 1σ u 2 2σ g 2 2σ u 2 1π u 4 3σ g ...
The fourth shell contains one 4s orbital, three 4p orbitals, five 4d orbitals, and seven 4f orbitals, thus leading to a capacity of 2×1 + 2×3 + 2×5 + 2×7 = 32. [30] Higher shells contain more types of orbitals that continue the pattern, but such types of orbitals are not filled in the ground states of known elements. [ 45 ]
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
• the red cobalt cation Co 2+ from Co(NO 3) 2 (see § Co) • the orange chromium oxyanion Cr 2 O 2− 7 from K 2 Cr 2 O 7 • the yellow chromium oxyanion CrO 2− 4 from K 2 CrO 4 • the turquoise nickel cation Ni 2+ from NiCl 2 • the blue copper cation Cu 2+ from CuSO 4