TotalComposition
type: Class
subclass of: Restriction

IUPACName
type: Class

ChemicalName
type: Class

SingleComponentComposition
type: Class
subclass of: Restriction

ChemicalSpecies
type: Class
equivalent class: Class
  union of:
    rest:
      rest:
        rest: nil
elucidation: Specific form of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure. Chemical species is the macroscopic equivalent of molecular entity and refers to sets or ensembles of molecular entities.
iupac doi: https://doi.org/10.1351/goldbook.CT06859
comment: Following nominalistic approach a species is simply a name that can point to an element name, a chemical formula or a chemical compound. So everything addressed by these classes of names can be calleded a chemical species.
comment: N2 Methane CH4 Fe Sodium Chloride

http://emmo.info/emmo/middle/materials#EMMO_21205421_5783_4d3e_81e5_10c5d894a88a
example: Hydrogen molecule is an adequate definition of a certain molecular entity for some purposes, whereas for others it is necessary to distinguish the electronic state and/or vibrational state and/or nuclear spin, etc. of the hydrogen molecule.
example: Methane, may mean a single molecule of CH4 (molecular entity) or a molar amount, specified or not (chemical species), participating in a reaction. The degree of precision necessary to describe a molecular entity depends on the context.
comment: Molecular entity is used as a general term for singular entities, irrespective of their nature, while chemical species stands for sets or ensembles of molecular entities. Note that the name of a compound may refer to the respective molecular entity or to the chemical species,

Heteronuclear
type: Class

Homonuclear
type: Class
alternative label: ElementalMolecule

MolecularFormula
type: Class
subclass of: Restriction
elucidation: An expression that provides information about the element types that constiture a molecule or a molecular substance and their number.
example: Hydrogen peroxide is H2O2

ElementalSubstance
type: Class
elucidation: A chemical substance composed of atoms with the same number of protons in the atomic nucleus.
iupac doi: https://doi.org/10.1351/goldbook.C01022
alternative label: PureSubstance

ChemicalEntity
type: Class
disjoint union of:
  rest:
    rest: nil
comment: A chemical entity comprises the two different ways to represents matter: as single recognizable particle entity (molecular entity) and as a composition of particle entities (substance). This distinction is not well assessed in actual chemical nomenclature, in which an element name refers to both the pure elemental substance or the atom. In the EMMO we force the adoption of a more strict categorization based on mereotopology. The class Material hosts the subclasses for which a substance can be identified without necessarily considering its nature of molecule/atom or substance (e.g. hydrocarbon is the class of both hydrocarbon molecules or gases).

InorganicCompound
type: Class

ChemicalElement
type: Class
subclass of: Restriction
  some values from: string
elucidation: The symbol for a specific chemical element, that can stand both for an atom or a substance.
iupac doi: https://doi.org/10.1351/goldbook.C01022
comment: The IUPAC Gold Book defines the a chemical element both as: - a species of atoms; all atoms with the same number of protons in the atomic nucleus - a pure chemical substance composed of atoms with the same number of protons in the atomic nucleus This qualifies a chemical element as a name and not a matter obejct that can stand for an atom or a substance.

ChemicalNomenclature
type: Class
elucidation: A language object following a specific nomenclature rules for defining univocal names of chemical compounds.
comment: A chemical numenclature should not be confused with the chemical formula.

HydrogenSymbol
type: Class
subclass of: Restriction
  has value: H

EmpiricalFormula
type: Class
elucidation: An expression that provide information about the element type of a compound and their relative ratio.
example: Hydrogen peroxide is HO

OrganicCompound
type: Class

ChemicalComposition
type: Class
disjoint union of:
  rest:
    rest:
      rest: nil
elucidation: A language construct that provides information about the consitutents of a substance and their fractions or amounts.

PartialComposition
type: Class
subclass of: Restriction

UraniumSymbol
type: Class
subclass of: Restriction
  has value: U

ArgonSymbol
type: Class
subclass of: Restriction
  has value: Ar

ChemicalMaterial
type: Class

IUPACNomencalture
type: Class

ChemicalFormula
type: Class
subclass of: Restriction
elucidation: A symbolic construct that provides informations about the chemical proportions of the elements that constitute a chemical compound or a specific molecule.
comment: A chemical formula may also include other symbols such as parentheses, plus and minus signs, brackets

ElementalMaterial
type: Class

ChemicalCompositionQuantity
type: Class

PhysicoChemical
type: Class

CategorizedPhysicalQuantity
type: Class

StructuralFormula
type: Class
elucidation: A graphical representation of a molecular structure showing the relative position in space of the atomic constituents and their bonds.

ChemicalRepresentation
type: Class
elucidation: A representation of objects belonging to the chemistry field.

Representation
type: Class
elucidation: A graphical object aimed to represent schematically the conceptual, tempral or spatial structure of another object.

Chemical
type: Class
elucidation: A language object that follows the syntactic rules used in the chemical field.

ChemicalSymbolicConstruct
type: Class
equivalent class: Class
  intersection of:
    rest:
      rest: nil

CondensedFormula
type: Class
example: An expression that provides information about the element types that constiture a molecule or a molecular substance and their number, together with simple information about the connectivity of its groups by using parenthesis or by goruping element names according to its molecular structure.

CASRN
type: Class
elucidation: Chemical Abstact Service registry number for a chemical substance from the American Chemical Society
example: Water is 7732-18-5

ChemicalSymbol
type: Class
equivalent class: Class
  intersection of:
    rest:
      rest: nil

InChI
type: Class
elucidation: The International Chemical Identifier (InChI) textual identifier proposed by IUPAC to provide a standard encoding for databases of molecular information.

ChemicalSubstance
type: Class
elucidation: Matter of constant composition best characterized by the entities (molecules, formula units, atoms) it is composed of.
iupac doi: https://doi.org/10.1351/goldbook.C01039
comment: A substance is always composed of more than one molecular entity. It lays in the continuum or mesoscopic domain.

ChemicalCompound
type: Class
disjoint union of:
  rest:
    rest: nil
elucidation: A chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds.
wikipedia entry: https://en.wikipedia.org/wiki/Chemical_compound

http://emmo.info/emmo/middle/materials#EMMO_eb77076b_a104_42ac_a065_798b2d2809ad
alternative label: ChemicalElement