What is Nomenclature: Definition and 104 Discussions

Nomenclature (UK: , US: ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal conventions of everyday speech to the internationally agreed principles, rules and recommendations that govern the formation and use of the specialist terms used in scientific and any other disciplines.Naming "things" is a part of general human communication using words and language: it is an aspect of everyday taxonomy as people distinguish the objects of their experience, together with their similarities and differences, which observers identify, name and classify. The use of names, as the many different kinds of nouns embedded in different languages, connects nomenclature to theoretical linguistics, while the way humans mentally structure the world in relation to word meanings and experience relates to the philosophy of language.
Onomastics, the study of proper names and their origins, includes: anthroponymy (concerned with human names, including personal names, surnames and nicknames); toponymy (the study of place names); and etymology (the derivation, history and use of names) as revealed through comparative and descriptive linguistics.
The scientific need for simple, stable and internationally accepted systems for naming objects of the natural world has generated many formal nomenclatural systems. Probably the best known of these nomenclatural systems are the five codes of biological nomenclature that govern the Latinized scientific names of organisms.

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  1. A

    Chemistry Choosing principal chain in the nomenclature of organic compounds

    In this question, I am not sure as to which of the following two chains should be considered as the principal chain. Approach 1 (7 carbon chain, 2 substituents): 4-methyl-4-(1,1-dimethylethyl)heptane Approach 2 (6 carbon chain, 4 substituents): 2,2,3-trimethyl-3-propylhexane Clearly, the...
  2. samy4408

    Searching for a reliable resource to practice IUPAC nomenclature

    Hello, I just learned the bases of IUPAC nomenclature and I couldn't find a good and reliable resource for problems to practice. if you know one please share it with me . thanks.
  3. ohwilleke

    I New Naming Rules for Exotic Hadrons at the LHC: LHCb Collaboration Paper (2022)

    The LHCb collaboration at the Large Hadron Collider has developed a new set of rules for naming composite particles bound by the strong force (i.e. hadrons) that are contemplated by existing rules for naming them. This has significant practical relevance to anyone dealing with high energy hadron...
  4. Vernii

    Nomenclature of organic compounds

    It is very important to recognize that, in general, the rules of the nomenclature of organic compounds are written in terms of classical valence bonding and do not imply electronic configurations of any kind. [Mentor Note -- Representative link added below]...
  5. S

    Chemistry Naming ethers: priority of alkyl substituent and ethoxy subsitutent

    When there is both alkyl substituent and ethoxy substituent in a single molecule, which one should be prioritized when numbering your base carbon chains? I am confused because the first structure below seems to have numbered the carbon attached to ethyl as the first carbon, while the second...
  6. ooookkkkk

    Chemistry Are S2Cl2 and SCl the same thing?

    I think S2Cl2 and SCl are the same thing, and SCl actually simpler and concise, so why do we have disulfur dichloride ?
  7. S

    Chemistry Drawing 1-bromo-6-chlorodispiro [2.1.2^5.1^3] octane

    I tried drawing the structure, and I do not know which one of the two is the correct compound for the nomenclature. Which one would be the correct one, and why? Thank you!
  8. S

    Nomenclature questions -- Naming structures when given compounds

    How would I name the following two compounds? My guess is that the first one would be 3-bromophenyl 1-chloro ketone and the second one (4Z)-3-sec butyl-hex-4-en-1-yne. Am I correct? Thank you
  9. S

    Chemistry IUPAC Naming of 3-Bromo Phenyl Chloro Ketone

    The following structure was given, and I have to name the compound. My guess is that the compound is called 3-bromo phenyl chloro ketone, but I am not sure. Can you tell me if my answer is correct, and also tell me how to tackle the IUPAC naming for this compound? Thank you!
  10. S

    Chemistry Deciding Carbon Numbering for (Z)-1-bromo-2-chloro-2-fluoro-1-iodoethene

    The following structure was given, and the answer was (z)-1-bromo-2-chloro-2-fluoro-1-iodoethene. But how do you decide which carbon is numbered 1 and the other 2? Thank you.
  11. S

    Chemistry Naming BrCH2CH2CH2OH: Excluding Carbon # for OH Group

    I thought that the compound would be named 2-bromo-propan-1-ol, but the answer sheet says that it is 3-bromopropanol. But don't you have to indicate the position of the OH group with carbon numbers? My textbook says that CH3CH2CH2OH would be named 1-propanol. Here, it seems like the position of...
  12. S

    Naming the pentane with phenyl group (or benzene with aryl group)

    I understand the first one, which indicates that there is a phenyl group in the second carbon of pentane. But where did the 2 in 2-pentylbenzene come from? Shouldn't if it be just pentylbenzene, since there is only one subtitute(pentane) on the benzene? If not, would you explain why? Thank you.
  13. S

    Chemistry Drawing the structure of 1,3,5 - trimethylphenol

    The picture above is the correct answer, but I do not understand why. I thought that the OH group on the top has to be prioritized and be numbered 1. But then, the structure would have to be named 2,4,6-trimethylphenol, not 1,3,5-trimethylphenol. For example, 4-chloroaniline structure looks...
  14. jk22

    I Nomenclature : global or constant phase

    Is the phase factor in : ##e^{i\phi}\Psi(x)## a constant or a global phase factor called ?
  15. K

    I Metric Nomenclature: Lorentz & Minkowski

    Can I say that the Lorentz metric is the specific form ##-c^2dt^2 + dx^2 + dy^2 + dz^2## whereas the Minkowski metric is the metric of Minkowski space which can take the Lorentz form I just gave, but can also, e.g., be written in spherical coordinates?
  16. Krushnaraj Pandya

    IUPAC Nomenclature: 2-Oxo-cyclopentanitrile or 2-Cyano-cyclopentanone?

    Homework Statement Which name is more correct, 2-oxo-cyclopentanitrile or 2-cyano-cyclopentanone 2. The attempt at a solution The priority of CN group is higher than ketone, so the first name should be correct but the second name is mentioned in my textbook
  17. Krushnaraj Pandya

    Can I Learn Organic Chemistry from a Textbook Alone?

    Homework Statement My only doubt while solving a larger problem is whether 4-Ethyl,3,3-Dimethyl Hexane and 3-Ethyl,4,4-Dimethyl Hexane equivalent?
  18. Wrichik Basu

    IUPAC Name of EDTA: 2,2′,2″,2′″-(ethane-1,2-diyldinitrilo-)κ^2N

    As per IUPAC Nomenclature of Inorganic Chemistry, the correct name of the edta chelate is $$\text{2,2′,2″,2′″-(ethane-1,2-diyldinitrilo-} κ^2 \text{N)tetraacetato-}κ^4O $$ As far as I know, edta coordinates through Nitrogen and Oxygen atoms, and there is no metal-carbon bond. On the other hand...
  19. Wrichik Basu

    Query on IUPAC nomenclature of coordination complexes

    I could finally get a copy of the Red Book 2005 from a library. In the chapter dedicated to nomenclature of coordinate complexes, while explaining the κ-system of specifying donor atoms, the following two examples were given (among many others): Can anyone explain how the naming is done for...
  20. pairofstrings

    Class, Interface, Abstract, Static, Partial, Sealed

    Hi. What do I call Instance Classes, Interface, Abstract Classes, Partial Classes, Static Class, Sealed Class collectively? Thanks.
  21. I

    Finding Formulas from Systematic Names: How Does the Number in Parentheses Help?

    Homework Statement Sodium chlorate(I) Sodium chlorate(V) Potassium nitride(III) Phosphorus(III) chloride Magnesium iodate(I) Homework Equations None The Attempt at a Solution I know the number in the bracket refers to what's before it, i.e. in sodium chlorate(V), the (V) means that the...
  22. donaldparida

    IUPAC nomenclature for many multiple bonds

    My previous Chemistry teacher while teaching IUPAC nomenclature said that the double bond is always given greater priority over the triple bond and the numbering of the carbon atom chain is done in such a way that the double bond gets the lowest possible number while my present Chemistry teacher...
  23. I

    Organic Chem Nomenclature (need an expert)

    Homework Statement Need help naming these 2 molecules: Homework EquationsThe Attempt at a Solution I think they are: ethoxycyclohexane 5-chloro-2-ethenyl-4-iodobenzonitrile
  24. W

    Define the notation used here in describing a series?

    Homework Statement "For the given series, write formulas for the sequences an , Sn, Rn and find the limit as n->∞ (if it exists) Homework Equations ∑∞1 ((1/n) - 1/(n+1) The Attempt at a Solution I know how to take the limit, that's no problem. I'm a bit confused about what an , Sn, Rn are...
  25. P

    Why can't we name this compound as 4-ethyl-5-methyloctane?

    5-ethyl-4-methyloctane. Why can't we name this compound as 4-ethyl-5-methyloctane?
  26. RoboNerd

    Quick question on IUPAC organic naming

    Hi everyone. I was bashing my head against this compound. I thought that the correct name for it was 4-ethyl-1-heptanol since apparently the longest parent chain has eight carbons. Could anyone please advise if my answer is correct, and if not, what I did wrong? Thanks in advance
  27. gracy

    Bicyclic compounds nomenclature

    Homework Statement Name the following molecule by the IUPAC system of nomenclature. Homework Equations There are some rules. To name bicyclic alkanes, you follow these three steps: 1- Count the total number of carbons in the entire molecule. This is the parent name (eg. ten carbons in the...
  28. kostoglotov

    Where does the nomenclature "eigen" originate?

    In eigenvectors, eigenvalues, eigenanalysis...why the word eigen and what's the history, how did these things come to have the prefix eigen? My best hunch is that the German word "eigen" means "own"...but that's not very illuminating.
  29. SadPanda6022

    Is I=Mk^2 the Same as I=mr^2 in Physics Nomenclature?

    Hey guys, quick question. I got confused in some nomenclature between some books and wanted to clarify somehow. A book I have has I=Mk^2 as defining a radius of gyration. Is this the same as I-mr^2? Terminology was just confusing me.Thanks guys.
  30. Calpalned

    Functions of more than one variable nomenclature

    Homework Statement Homework Equations n/a The Attempt at a Solution ##y'=f(x.y)## is a function of two variables. ##y=y(x)## is a function of only one variable. How can they be related? Clearly ##y(x) = f(x) \neq f(x,y)## Thanks
  31. H

    Nomenclature phsyics questions

    How is this nomenclature read and what is the meaning of the alpha and the n? quote below In terms of the absolute 182Hf abundance, howevever, only AGB (asymptotic giant branch) models of mass ~2 to 4 solar masses are major producers of s process 182Hf in the Galaxy, owing to the combined...
  32. Priyadarshini

    What is the IUPAC nomenclature for the given aromatic compound?

    Homework Statement Give the IUPAC nomenclature of the following compound (in the attachment) (sorry, i don't know why the picture has become upside down!) The Attempt at a Solution Shouldn't the answer be 1-phenyl-2,3-dibromopentane? The book says it is 2,3-dibromo-1-phenylpentane.
  33. M

    Is there a difference between an electron anti-neutrino and a positron neutrino?

    Is an electron anti neutrino and a positron neutrino the same thing?
  34. C

    How many topologies exist on 4 points? Any nomenclature?

    Just for fun, I tried enumerating the topologies on n points, for small n. I found that if the space X consists of 1 point, there is only one topology, and for n = 2, there are four topologies, although two are "isomorphic" in some sense. For n = 3, I I found 26 topologies, of 7 types. For n...
  35. K

    Organic Chemistry Nomenclature

    Homework Statement Provide an acceptable name for the alkane shown below. Homework Equations N/A The Attempt at a Solution I never get these right but...my guess would be 2-dimethyl-5-butononane? My reasoning: the longest carbon chain has 9 carbons so the base name would be nonane, there...
  36. DiracPool

    Coulomb potential in hydrogen atom nomenclature

    I'm seeing a version of the potential as -Ze^2/4πεr. My question is what exactly does the Ze^2 refer to? I think the e^2 is supposed to represent the proton and the neutron, and the Z is supposed to represent the number of protons, but I'm not sure how to read it. Does e refer to the charge...
  37. A

    Use of Carb- Prefix before functional group names?

    1. I have been facing problem with the use of carb-prefix under same special conditions in organic chemistry nomenclature.Homework Equations3. One friend of mine suggested me that if there are 3 or more similar functional group, out of which none can be given priority in a single structure, then...
  38. A

    IUPAC naming - choosing the main branch doubts

    What are the rules for choosing main branch ? Wikipedia states - "Identification of the parent hydrocarbon chain. This chain must obey the following rules, in order of precedence: 1 It should have the maximum number of substituents of the suffix functional group. By suffix, it is meant that...
  39. snatchingthepi

    Understanding Conjugate Momentum: Exploring the Nomenclature

    So I'm studying for my CM final and in looking over the section on ignorable coordinates and generalized momenta I come across the definition for conjugate momentum p_{i} = \frac{\partial L}{\partial \dot{q_{i}}} My question is simple - why is it called 'conjugate'? I just never really thought...
  40. S

    Why Are Liquid Properties in Steam Tables Labeled with an 'f' Subscript?

    I'm curious as to why steam tables typically present liquid properties with an "f" subscript, such as ρf.The gas properties use a "g" subscript, so I would expect the liquid properties to use "l". My first guess at the meaning of the "f" would be that it means "fluid", but this wouldn't make...
  41. BrainMan

    Pb(MnO4)2: Lead Permanganate Formula

    Homework Statement Write the formula of : lead(2) permanganateHomework Equations The Attempt at a Solution So I know that this formula is the combination of lead magnesium and oxygen. I know that the -ate suffix means that it has the most number of oxygen ions possible. The answer was Pb...
  42. Q

    Nomenclature - IUPAC and Common Names

    Homework Statement What if we stuck with the IUPAC name and called the isopropyl group a 1-methylethyl group? That would definitely reverse the alphabetical priorities; because the substituents here on the hydrocarbon are on equivalent positions, we must give the lower number to the...
  43. gfd43tg

    Op Amp Inverting/Non-inverting terminal nomenclature

    Hello, I am wondering why the inverting terminal is the negative terminal and the non-inverting terminal is the positive terminal by name?
  44. F

    On the IUPAC nomenclature of ethers and esters

    Hello, I was wondering if there is a systematic procedure to follow when naming complex organic molecules containing ethers and esters. By "complex" I mean organic molecules that contain multiple ether/ester groups and possibly within multiple different branches of the molecule. 1.How to...
  45. J

    IUPAC Rules for Alkene Nomenclature: Naming (Z)-3-methyl-3-butene and Isobutene

    Homework Statement Give the name for the given molecule Homework Equations Following IUPAC rules for alkene nomenclature... The Attempt at a Solution (Z)-3-methyl-3-butene Might be an isobutene? Any help is well appreciated, thank you!
  46. V

    Learn Inorganic Compound Nomenclature with IUPAC

    I think one of the most important aspects of learning is knowing how to organize information in your head. And after all this time I realized I don't know the rules behind chemical nomenclature as well as I should; for instance, I can name chemical compounds just 'cause, having no idea why that...
  47. Monique

    Ambiguous gene/protein nomenclature

    I'm writing a paper and run into the issue that co-authors claim that certain genes have different names as a protein :confused: Like the CREBBP gene, encodes CRB protein? As far as I know the gene encodes for a single protein, who in the right mind would give it a different name? I'm for...
  48. joema

    Origin of phase angle nomenclature?

    It's common to express phase differences between two sinusoidal waveforms as a "phase angle", with a full cycle corresponding to 360 degrees. What is the origin of this nomenclature, and why is phase expressed in degrees? Examined naively, the time domain representation of two waveforms...
  49. T

    What Defines a Theorem as Opposed to a Law in Mathematics?

    From the perspective of mathematical philosophy, what is the difference between a "theorem" and a "law"? In particular, I'm wondering if there is a difference between what makes the Pythagorean Theorem a "theorem" and the Law of Cosines a "law". Thanks.
  50. S

    Organic Chemistry - Nomenclature Question

    Homework Statement (see uploaded attachment for picture). I basically have to name this molecule. The Attempt at a Solution I don't know where to start counting for the longest carbon chain and I'm not sure if it's a nonane or octane. If you guys can help it'd be much appreciated