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The alkali metals dissolve slowly in liquid ammonia, forming ammoniacal solutions of solvated metal cation M + and solvated electron e −, which react to form hydrogen gas and the alkali metal amide (MNH 2, where M represents an alkali metal): this was first noted by Humphry Davy in 1809 and rediscovered by W. Weyl in 1864.
The results would have astounded him – the same elements that combined according to von Liebig's method, when combined according to Wöhler's method made two completely different compounds. Wöhler and von Liebig had inadvertently discovered isomerism : the same number of atoms of the same elements combining in different ways to make ...
For the alkali metals, amalgamation is exothermic, and distinct chemical forms can be identified, such as KHg and KHg 2. [4] KHg is a gold-coloured compound with a melting point of 178 °C, and KHg 2 a silver-coloured compound with a melting point of 278 °C. These amalgams are very sensitive to air and water, but can be worked with under dry ...
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]
It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called blocks. Elements in the ...
Germanium cluster anions (Zintl ions) such as Ge 4 2−, Ge 9 4−, Ge 9 2−, [(Ge 9) 2] 6− have been prepared by the extraction from alloys containing alkali metals and germanium in liquid ammonia in the presence of ethylenediamine or a cryptand. [42] [44] The oxidation states of the element in these ions are not integers—similar to the ...
In chemistry, an arsenide is a compound of arsenic with a less electronegative element or elements. Many metals form binary compounds containing arsenic, and these are called arsenides. They exist with many stoichiometries, and in this respect arsenides are similar to phosphides. [1]
The first two members of the group share similar properties as they are solid metals under standard conditions. Mercury is the only metal that is known to be a liquid at room temperature – as copernicium's boiling point has not yet been measured accurately enough, [ note 2 ] it is not yet known whether it is a liquid or a gas under standard ...