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The structure is related to that of zirconium orthosilicate (zircon): Ca 2+ is 8-coordinate, SO 2− 4 is tetrahedral, O is 3-coordinate. CaSO 4 ·2H 2 O (gypsum and selenite (mineral)): dihydrate. [7] CaSO 4 · 1 / 2 H 2 O : hemihydrate, also known as plaster of Paris. Specific hemihydrates are sometimes distinguished: α-hemihydrate ...
The Ca 2+ concentration of the vacuole may reach millimolar levels. The most striking use of Ca 2+ ions as a structural element in algae occurs in the marine coccolithophores, which use Ca 2+ to form the calcium carbonate plates, with which they are covered. Calcium is needed to form the pectin in the middle lamella of newly formed cells.
A calcium atom has twenty electrons, with electron configuration [Ar]4s 2. Like the other elements placed in group 2 of the periodic table, calcium has two valence electrons in the outermost s-orbital, which are very easily lost in chemical reactions to form a dipositive ion with the stable electron configuration of a noble gas, in this case ...
Selenium, which is an essential element for animals and prokaryotes and is a beneficial element for many plants, is the least-common of all the elements essential to life. [ 3 ] [ 63 ] Selenium acts as the catalytic center of several antioxidant enzymes, such as glutathione peroxidase , [ 11 ] and plays a wide variety of other biological roles .
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO 4 ·2H 2 O. [4] It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk.
Hagfish maintain an internal ion composition plasma that differs from that of seawater. The internal ionic environment of hagfish contains a lower concentration of divalent ions (Ca2+, Mg2+, SO4 2-) and a slightly higher concentration of monovalent ions. [5] Hagfish therefore have to expend some energy for osmoregulation.
Winter brings less daylight and colder temperatures, which can disrupt sleep. Seasonal Affective Disorder (SAD) is more common in winter due to the lack of sunlight, causing sleep disturbances.
CA2, CA-2 or CA II may refer to : Carbonic anhydrase II, a human gene; United States Court of Appeals for the Second Circuit; California's 2nd congressional district; Hummel CA-2, an ultralight aircraft; California State Route 2; Ca II, a singly-ionized calcium that produces the H and K lines, and the calcium triplet lines in the spectrum of ...