periódica

Periódica is the feminine form of the adjective periodic in Spanish and Portuguese, used to describe phenomena, objects, or events that recur at regular intervals. Its etymology traces to Latin periodicus, from Greek periodos, meaning a cycle or way around. In both languages the term appears across scientific and everyday contexts to mark regular repetition or recurrence.

In Spanish, common uses include phrases such as tabla periódica (periodic table), función periódica (periodic function), ciclos periódicos (periodic cycles), and tareas periódicas (periodic tasks). The word can describe regular reports or publications, as in informes periódicos, though as a standalone noun it is more typical to use periódico (newspaper) or publicación periódica (periodical publication). In Portuguese, equivalent constructions are tabela periódica, função periódica, ciclo periódico and atividades periódicas, with relatórios periódicos for regular reports.

In science and mathematics, periodicity denotes repeating patterns. A periodic function f has a nonzero period T with f(x+T) = f(x) for all x. In chemistry and related fields, the phrase tabla periódica is central, organizing elements by recurring chemical properties across periods and groups. The concept also appears in biology, physics, and signal processing to describe rhythms, cycles, or recurring structures.

See also: periodic table, periodic function, period, cyclic. Overall, periodicity as a concept captures regular repetition, whether describing natural phenomena, mathematical functions, or organized scientific knowledge.