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  2. Conversion (chemistry) - Wikipedia

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

    Conversion and its related terms yield and selectivity are important terms in chemical reaction engineering.They are described as ratios of how much of a reactant has reacted (X — conversion, normally between zero and one), how much of a desired product was formed (Y — yield, normally also between zero and one) and how much desired product was formed in ratio to the undesired product(s) (S ...

  3. Equivalent (chemistry) - Wikipedia

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

    The solution has 1 mole or 1 equiv Na +, 1 mole or 2 equiv Ca 2+, and 3 mole or 3 equiv Cl −. An earlier definition, used especially for chemical elements , holds that an equivalent is the amount of a substance that will react with 1 g (0.035 oz) of hydrogen , 8 g (0.28 oz) of oxygen , or 35.5 g (1.25 oz) of chlorine —or that will displace ...

  4. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    The difference is quite significant when dealing with gases, and it is very important to specify which quantity is being used. For example, the conversion factor between a mass fraction of 1 ppb and a mole fraction of 1 ppb is about 4.7 for the greenhouse gas CFC-11 in air (Molar mass of CFC-11 / Mean molar mass of air = 137.368 / 28.97 = 4.74 ...

  5. Conversion of units - Wikipedia

    en.wikipedia.org/wiki/Conversion_of_units

    Conversion of units is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to include replacement of a quantity with a corresponding quantity that describes the same physical property.

  6. List of unsolved problems in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_unsolved_problems...

    Protein folding problem: Is it possible to predict the secondary, tertiary and quaternary structure of a polypeptide sequence based solely on the sequence and environmental information? Inverse protein-folding problem: Is it possible to design a polypeptide sequence which will adopt a given structure under certain environmental conditions?

  7. Internal conversion (chemistry) - Wikipedia

    en.wikipedia.org/.../Internal_conversion_(chemistry)

    Internal conversion is a transition from a higher to a lower electronic state in a molecule or atom. [1] It is sometimes called "radiationless de-excitation", because no photons are emitted. It differs from intersystem crossing in that, while both are radiationless methods of de-excitation, the molecular spin state for internal conversion ...

  8. Quantities, Units and Symbols in Physical Chemistry

    en.wikipedia.org/wiki/Quantities,_Units_and...

    Quantities, Units and Symbols in Physical Chemistry, also known as the Green Book, is a compilation of terms and symbols widely used in the field of physical chemistry. It also includes a table of physical constants , tables listing the properties of elementary particles , chemical elements , and nuclides , and information about conversion ...

  9. Nuclear transmutation - Wikipedia

    en.wikipedia.org/wiki/Nuclear_transmutation

    The term transmutation dates back to alchemy.Alchemists pursued the philosopher's stone, capable of chrysopoeia – the transformation of base metals into gold. [3] While alchemists often understood chrysopoeia as a metaphor for a mystical or religious process, some practitioners adopted a literal interpretation and tried to make gold through physical experimentation.