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  2. Evolution of metal ions in biological systems - Wikipedia

    en.wikipedia.org/wiki/Evolution_of_Metal_Ions_in...

    The Earth began as an iron aquatic world with low oxygen. The Great Oxygenation Event occurred approximately 2.4 Ga (billion years ago) as cyanobacteria and photosynthetic life induced the presence of dioxygen in the planet's atmosphere. Iron became insoluble (as did other metals) and scarce while other metals became soluble.

  3. Roussin's red salt - Wikipedia

    en.wikipedia.org/wiki/Roussin's_red_salt

    The salt can be prepared by the reaction of sulfide salts with iron nitrosyl halides: [7] Fe 2 I 2 (NO) 4 + 2Li 2 S → Li 2 Fe 2 S 2 (NO) 4 + 2LiI. Another way to obtain Roussin's red salt is to alkalize a solution of the related compound Roussin's black salt, K[Fe 4 S 3 (NO) 7], using a suitable base: 2K[Fe 4 S 3 (NO) 7] + 4KOH → 3K 2 [Fe 2 ...

  4. Chemical coloring of metals - Wikipedia

    en.wikipedia.org/wiki/Chemical_coloring_of_metals

    Chemical coloring of metals is the process of changing the color of metal surfaces with different chemical solutions. The chemical coloring of metals can be split into three types: electroplating – coating the metal surface with another metal using electrolysis. patination – chemically reacting the metal surface to form a colored oxide or ...

  5. Salt (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Salt_(chemistry)

    Many metals such as the alkali metals react directly with the electronegative halogens gases to form salts. [7] [8] Salts form upon evaporation of their solutions. [9] Once the solution is supersaturated and the solid compound nucleates. [9] This process occurs widely in nature and is the means of formation of the evaporite minerals. [10]

  6. Salt metathesis reaction - Wikipedia

    en.wikipedia.org/wiki/Salt_metathesis_reaction

    This reaction usually produces a salt. One example, hydrochloric acid reacts with disodium iron tetracarbonyl to produce the iron dihydride: 2 HCl + Na 2 Fe(CO) 4 → 2 NaCl + H 2 Fe(CO) 4. Reaction between an acid and a carbonate or bicarbonate salt yields carbonic acid, which spontaneously decomposes into carbon dioxide and water. The release ...

  7. Transition metal thiolate complex - Wikipedia

    en.wikipedia.org/wiki/Transition_metal_thiolate...

    Metal thiolate complexes are commonly prepared by reactions of metal complexes with thiols (RSH), thiolates (RS −), and disulfides (R 2 S 2). The salt metathesis reaction route is common. In this method, an alkali metal thiolate is treated with a transition metal halide to produce an alkali metal halide and the metal thiolate complex:

  8. Iron - Wikipedia

    en.wikipedia.org/wiki/Iron

    As such, iron is the most abundant element in the core of red giants, and is the most abundant metal in iron meteorites and in the dense metal cores of planets such as Earth. [29] It is also very common in the universe, relative to other stable metals of approximately the same atomic weight.

  9. Titanium dioxide - Wikipedia

    en.wikipedia.org/wiki/Titanium_dioxide

    When used as a food coloring, it has E number E171. World production in 2014 exceeded 9 million tonnes. World production in 2014 exceeded 9 million tonnes. [ 5 ] [ 6 ] [ 7 ] It has been estimated that titanium dioxide is used in two-thirds of all pigments, and pigments based on the oxide have been valued at a price of $13.2 billion.