periodických

Periodických is the genitive plural form of the Czech adjective periodický, meaning periodic. In Czech, adjectives agree with the nouns they modify in gender, number, and case, so periodických appears when the noun is plural and in the genitive case. This form is typical for adjectives ending in -ický and is used across various domains, including science, literature, and everyday language, whenever a plural noun is described as having a regular or repeating interval or cycle.

Etymology and meaning: The root period- derives from Latin and Greek concepts of a period or cycle, common in terms like perioda or periodus. The Czech suffix -ický forms many adjectives describing relations to a root concept (perioda, periodický), and the genitive plural ending -ických marks agreement with a plural noun in that case.

Usage in sentences: The form appears in phrases such as periodických tabulek (of periodic tables), periodických jevů (of periodic phenomena), or periodických vzorců (of periodic patterns). It is used in formal and technical writing to specify that multiple items share a periodic characteristic or relation.

Grammar notes: periodických is an inflected adjective form and cannot function as a stand-alone noun. Its citation form is periodický. The corresponding adverb is periodicky, meaning “periodically.” Other case forms of periodický vary according to gender and number of the noun they modify.

See also: periodický, periodic table, periodic function, Czech grammar.