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  2. Stereoselectivity - Wikipedia

    en.wikipedia.org/wiki/Stereoselectivity

    In chemistry, stereoselectivity [1] is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereoisomers during a non-stereospecific creation of a new stereocenter or during a non-stereospecific transformation of a pre-existing one. [2]

  3. Isomerization - Wikipedia

    en.wikipedia.org/wiki/Isomerization

    In chemistry, isomerization or isomerisation is the process in which a molecule, polyatomic ion or molecular fragment is transformed into an isomer with a different chemical structure. [1] Enolization is an example of isomerization, as is tautomerization .

  4. Cis–trans isomerism - Wikipedia

    en.wikipedia.org/wiki/Cis–trans_isomerism

    Another example of this is the relationship between oleic acid and elaidic acid; oleic acid, the cis isomer, has a melting point of 13.4 °C, making it a liquid at room temperature, while the trans isomer, elaidic acid, has the much higher melting point of 43 °C, due to the straighter trans isomer being able to pack more tightly, and is solid ...

  5. Image (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Image_(mathematics)

    The image of the function is the set of all output values it may produce, that is, the image of . The preimage of f {\displaystyle f} , that is, the preimage of Y {\displaystyle Y} under f {\displaystyle f} , always equals X {\displaystyle X} (the domain of f {\displaystyle f} ); therefore, the former notion is rarely used.

  6. Umpolung - Wikipedia

    en.wikipedia.org/wiki/Umpolung

    Dithiane chemistry. Dithiane chemistry opens the way to many new chemical transformations. One example is found in so-called anion relay chemistry in which a negative charge of an anionic functional group resulting from one organic reaction is transferred to a different location within the same carbon framework and available for secondary ...

  7. Chemical reaction - Wikipedia

    en.wikipedia.org/wiki/Chemical_reaction

    Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents.

  8. Nucleosynthesis - Wikipedia

    en.wikipedia.org/wiki/Nucleosynthesis

    Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang , through nuclear reactions in a process called Big Bang nucleosynthesis . [ 1 ]

  9. Photochemistry - Wikipedia

    en.wikipedia.org/wiki/Photochemistry

    Photochemical immersion well reactor (50 mL) with a mercury-vapor lamp.. Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750 nm), or infrared radiation (750–2500 nm).