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The Periodic Table of Videos has filmed at least one video for each of the 118 elements (from hydrogen to oganesson). [13] They have also filmed several videos that discuss molecules such as D 2 O (heavy water) [14] and sulfuric acid. [15] Also filmed are "Chem definitions" that provide an explanation to words that are used in chemistry.
Sodium metal is highly reducing, with the standard reduction potential for the Na + /Na couple being −2.71 volts, [3] though potassium and lithium have even more negative potentials. [4] The thermal, fluidic, chemical, and nuclear properties of molten sodium metal have caused it to be one of the main coolants of choice for the fast breeder ...
While most metals form arsenides, only the alkali and alkaline earth metals form mostly ionic arsenides. The structure of Na 3 As is complex with unusually short Na–Na distances of 328–330 pm which are shorter than in sodium metal, and this indicates that even with these electropositive metals the bonding cannot be straightforwardly ionic. [10]
In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form hydroxide ions OH −. These ions can react with hydrogen ions (H + according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Ca(OH) 2.
Potassium was the first metal that was isolated by electrolysis. [45] Later in the same year, Davy reported extraction of the metal sodium from a mineral derivative (caustic soda, NaOH, or lye) rather than a plant salt, by a similar technique, demonstrating that the elements, and thus the salts, are different.
a Group 1 is composed of hydrogen (H) and the alkali metals. Elements of the group have one s-electron in the outer electron shell. Hydrogen is not considered to be an alkali metal as it is not a metal, though it is more analogous to them than any other group. This makes the group somewhat exceptional.
An alkalide is a chemical compound in which alkali metal atoms are anions (negative ions) with a charge or oxidation state of −1. Until the first discovery of alkalides in the 1970s, [1] [2] [3] alkali metals were known to appear in salts only as cations (positive ions) with a charge or oxidation state of +1. [4]
The alkali metals form orange-red monoclinic crystals as a double salt with ceric nitrate: M 2 [Ce(NO 3) 6] with M=K, Rb, Cs, or [NH 4]. [10] Ceric ammonium nitrate contains the icosahedral shaped ion [Ce(NO 3) 6] 2− which has cerium in the +4 oxidation state. [31] It is used as a reagent in oxidimetry. [9] Ceric potassium nitrate K 2 [Ce(NO 3)