täisolekule

Täisolekule (Finnish for "full molecule") is a term used in Finnish chemistry to describe a molecule in which all atoms have achieved a complete valence by forming covalent bonds, resulting in a saturated structure with no multiple bonds or rings that would leave valence unsatisfied. In practice, the concept is often applied to hydrocarbons, where a täisolekule corresponds to a saturated molecule similar to an alkane.

Definition and characteristics: A täisolekule is typically composed of atoms linked by single bonds only, with each atom’s usual valence fulfilled. In hydrocarbons, this leads to carbon atoms in sp3 hybridization and a formula of the form CnH2n+2 for acyclic compounds. The structure is generally flexible, allowing free rotation around single bonds, and it tends to be relatively chemically stable.

Examples: Common examples include methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10). These molecules contain no double or triple bonds and have the maximum number of hydrogen atoms for their carbon skeleton.

Contrast with unsaturated molecules: Unsaturated molecules contain pi bonds (double or triple bonds) or rings, and thus have fewer hydrogens relative to their carbon count. Examples include ethene (C2H4) and benzene (C6H6). Such compounds are not considered täisolekule.

Usage and notes: The term is primarily used in Finnish educational contexts to illustrate the concept of saturation. In English-language chemistry, it corresponds to “saturated molecule” or “alkane-type” compounds, depending on the context. See also: saturated hydrocarbon, alkanes, valence.