Periodic

Periodic (pẽr`i*od"ik) , adjective

[Prefix per- + iodic.]

(Chemistry) Pertaining to, derived from, or designating, the highest oxygen acid (HIO4) of iodine.

Periodic (pē`ri*od"ik) , adjective

[Latin periodicus, Greek periodiko`s: compare French périodique.]

Of or pertaining to a period or periods, or to division by periods.

The periodical times of all the satellites. — Sir J. Herschel

Performed in a period, or regular revolution; proceeding in a series of successive circuits; as, the periodical motion of the planets round the sun.

Happening, by revolution, at a stated time; returning regularly, after a certain period of time.

The periodic return of a plant's flowering. — Henslow

To influence opinion through the periodical press. — Courthope

Acting, happening, or appearing, at fixed or somewhat variable intervals; recurring; as, periodical epidemics

(Rhetoric) Of or pertaining to a period; constituting a complete sentence.

Note: A modern version of the periodic table can be found at: https://iupac.org/what-we-do/periodic-table-of-elements/

A similar relation had been enunciated in a crude way by Newlands; but the law in its effective form was developed and elaborated by Mendelejeff, whence it is sometimes called Mendelejeff's law. Important extensions of it were also made by L. Meyer. By this means Mendelejeff predicted with remarkable accuracy the hypothetical elements ekaboron, ekaluminium, and ekasilicon, afterwards discovered and named respectively scandium, gallium, and germanium.

Also: Periodical