Ionisissa

Ionisissa is the plural inessive form of the Finnish noun ioni, meaning ion. It is used to express the location “in the ions” or “within the ions” when referring to more than one ion. In Finnish, the inessive case marks location or state, and the plural suffix for inessive is -issa/-issä, chosen by vowel harmony; with the stem ioni the result is ionisissa.

The form primarily appears in scientific and technical contexts, such as chemistry, physics, and electrochemistry, where discussions involve multiple ions. Its meaning is grammatical rather than lexical beyond identifying a set of ions being referred to. For example, a sentence like ionit liikkuvat ionisissa liuoksissa translates to “ions move in ionic solutions,” illustrating how the plural inessive describes position within a collective of ions.

In ordinary Finnish prose, ionisissa is not a commonly used everyday noun but a standard inflected form of a technical noun. It demonstrates how Finnish uses the inessive suffix to indicate location and how plural forms are constructed for scientific terminology. When encountered, its interpretation should be tied to the broader discussion of ions and their environment rather than to any standalone concept specific to the word itself.

See also: Finnish grammar, Inessive case, Ion (ioni), Ionization.