When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Hydrohalogenation - Wikipedia

    en.wikipedia.org/wiki/Hydrohalogenation

    Hydrohalogenation. A hydrohalogenation reaction is the electrophilic addition of hydrogen halides like hydrogen chloride or hydrogen bromide to alkenes to yield the corresponding haloalkanes. [1][2][3] If the two carbon atoms at the double bond are linked to a different number of hydrogen atoms, the halogen is found preferentially at the carbon ...

  3. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    The geologic time scale is a way of representing deep time based on events that have occurred throughout Earth's history, a time span of about 4.54 ± 0.05 Ga (4.54 billion years). [3] It chronologically organises strata, and subsequently time, by observing fundamental changes in stratigraphy that correspond to major geological or ...

  4. Halogenation - Wikipedia

    en.wikipedia.org/wiki/Halogenation

    Halogenation. In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide -containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. [1] This kind of conversion is in fact so common that a comprehensive overview is ...

  5. Alkene - Wikipedia

    en.wikipedia.org/wiki/Alkene

    Alkene. In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon –carbon double bond. [1] The double bond may be internal or in the terminal position. Terminal alkenes are also known as α-olefins. The International Union of Pure and Applied Chemistry (IUPAC) recommends using the name "alkene" only for acyclic ...

  6. Haloform reaction - Wikipedia

    en.wikipedia.org/wiki/Haloform_reaction

    haloform-reaction. RSC ontology ID. RXNO:0000689. In chemistry, the haloform reaction (also referred to as the Lieben haloform reaction) is a chemical reaction in which a haloform (CHX3, where X is a halogen) is produced by the exhaustive halogenation of an acetyl group (R−C (=O)CH3, where R can be either a hydrogen atom, an alkyl or an aryl ...

  7. Hunsdiecker reaction - Wikipedia

    en.wikipedia.org/wiki/Hunsdiecker_reaction

    RXNO:0000106. The Hunsdiecker reaction (also called the Borodin reaction or the Hunsdiecker–Borodin reaction) is a name reaction in organic chemistry whereby silver salts of carboxylic acids react with a halogen to produce an organic halide. [1] It is an example of both a decarboxylation and a halogenation reaction as the product has one ...

  8. Electrophilic halogenation - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_halogenation

    Electrophilic halogenation. In organic chemistry, an electrophilic aromatic halogenation is a type of electrophilic aromatic substitution. This organic reaction is typical of aromatic compounds and a very useful method for adding substituents to an aromatic system. A few types of aromatic compounds, such as phenol, will react without a catalyst ...

  9. Lunar geologic timescale - Wikipedia

    en.wikipedia.org/wiki/Lunar_geologic_timescale

    Axis scale: Millions of years ago. The lunar geological timescale (or selenological timescale) divides the history of Earth 's Moon into five generally recognized periods: the Copernican, Eratosthenian, Imbrian (Late and Early epochs), Nectarian, and Pre-Nectarian. The boundaries of this time scale are related to large impact events that have ...