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The π-bond in the ethylene molecule is responsible for its useful reactivity. The double bond is a region of high electron density , thus it is susceptible to attack by electrophiles . Many reactions of ethylene are catalyzed by transition metals, which bind transiently to the ethylene using both the π and π* orbitals.
Cyanobacteria such as these carry out photosynthesis.Their emergence foreshadowed the evolution of many photosynthetic plants and oxygenated Earth's atmosphere.. Biological carbon fixation, or сarbon assimilation, is the process by which living organisms convert inorganic carbon (particularly carbon dioxide, CO 2) to organic compounds.
For example, photo-fermentation with Rhodobacter sphaeroides SH2C can be employed to convert small molecular fatty acids into hydrogen. [4] Enterobacter aerogenes is an outstanding hydrogen producer. It is an anaerobic facultative and mesophilic bacterium that is able to consume different sugars and in contrast to cultivation of strict ...
Microbial hydrogen production. Biohydrogen is H 2 that is produced biologically. [1] Interest is high in this technology because H 2 is a clean fuel and can be readily produced from certain kinds of biomass, [2] including biological waste. [3]
Four-carbon molecules are based on a skeleton made from four carbon atoms. They may be in a chain, branched chains, cycles or even bicyclic compounds C 4 H 4 isomers with CAS registry numbers
Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and >90% by number of atoms. [96] In astrophysics, neutral hydrogen in the interstellar medium is called H I and ionized hydrogen is called H II. [97] Radiation from stars ionizes H I to H II, creating spheres of ionized H II ...
Acetylene (systematic name: ethyne) is the chemical compound with the formula C 2 H 2 and structure H−C≡C−H.It is a hydrocarbon and the simplest alkyne. [8] This colorless gas is widely used as a fuel and a chemical building block.
Pure water is an example of a chemical substance, with a constant composition of two hydrogen atoms bonded to a single oxygen atom (i.e. H 2 O). The atomic ratio of hydrogen to oxygen is always 2:1 in every molecule of water. Pure water will tend to boil near 100 °C