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  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Fluorescein aqueous solutions, diluted from 10 000 to 1 part per million in intervals of ten-fold dilution. At 10 000 ppm the solution is a deep red colour. As the concentration decreases the colour becomes orange, then a vibrant yellow, with the final 1 ppm sample a very pale yellow.

  3. List of chemical databases - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_databases

    list of suppliers and catalog numbers "eMolecules". 8,000,000 [5] ENCS Japanese Existing and New Chemical Substances Inventory: regulated chemicals "ENCS (in Japanese)". Evaluated Kinetic Data IUPAC: rate constants curated "Evaluated Kinetic Data". FDA SRS Food and Drug Administration Substance Registration System U.S. National Library of Medicine

  4. Chemical shift - Wikipedia

    en.wikipedia.org/wiki/Chemical_shift

    Chemical shift δ is usually expressed in parts per million (ppm) by frequency, because it is calculated from [5] =, where ν sample is the absolute resonance frequency of the sample, and ν ref is the absolute resonance frequency of a standard reference compound, measured in the same applied magnetic field B 0.

  5. PubChem - Wikipedia

    en.wikipedia.org/wiki/PubChem

    Substances, 293 million entries [5] (up from 236 million entries in 2017 [7] and 163 million in Sept. 2014 [8]), contains also mixtures, extracts, complexes and uncharacterized substances. BioAssay, bioactivity results from 1.25 million [ 9 ] (up from 6,000 in Sept. 2014 [ 10 ] ) high-throughput screening programs with several million values.

  6. Template:Parts per million - Wikipedia

    en.wikipedia.org/wiki/Template:Parts_per_million

    Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more

  7. Strain (chemistry) - Wikipedia

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

    The strain energy of cyclopropane and cyclobutane are 27.5 and 26.3 kcal mol −1, respectively. [1] Cyclopentane experiences much less strain, mainly due to torsional strain from eclipsed hydrogens: its preferred conformations interconvert by a process called pseudorotation. [4]: 14 Ring strain can be considerably higher in bicyclic systems.

  8. Talk:Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Talk:Parts-per_notation

    The examples don't seem to be too accurate. A drop is usually defined as 0.05 ml, which then gives;. 1 drop in 50 ml = 1‰, 50ml is a very small cup 1 drop in 50 l = 1ppm 50 l is about 11 gallons, not 40 1 drop in 50 cubic metres = 1 ppb 1 drop = 1ppt, a 50 m swimming pool is 50*25*2 = 2,500 m^3 1 drop in 50,000,000 cubic metres = 1ppq, 50,000,000 m^3 is equivalent to a lake covering a square ...

  9. Cannabis cultivation - Wikipedia

    en.wikipedia.org/wiki/Cannabis_cultivation

    Cultivation of cannabis is the production of cannabis infructescences ("buds" or "leaves"). Cultivation techniques for other purposes (such as hemp production) differ.. In the United States, all cannabis products in a regulated market must be grown in the state where they are sold because federal law continues to ban interstate cannabis sales.