Atom Definition. An atom is the defining structure of an element, which cannot be broken by any chemical means. A typical atom consists of a nucleus of protons and neutrons with electrons orbiting this nucleus. However, an atom can consist of a single proton (i.e., the protium isotope of hydrogen) as a nucleus.
Mosaic art flourished in the Byzantine Empire from the 6th to the 15th centuries; that tradition was adopted by the Norman kingdom in Sicily in the 12th century, by eastern-influenced Venice, and among the Rus in Ukraine.osaic is an art form which uses small pieces of materials placed together to create a unified whole. The materials commonly used are marble or other stone, glass, pottery, mirror or foil-backed glass, or shells.
c.1400, from Old French mosaicq mosaic work, from Italian mosaico, from Medieval Latin musaicum mosaic work, work of the Muses, noun use of neuter of musaicus of the Muses, from Latin Musa (see muse). Medieval mosaics were often dedicated to the Muses. The word formed in Medieval Latin as though from Greek, but the (late) Greek word for mosaic work was mouseion (Klein says this sense was borrowed from Latin). Figurative use is from 1640s. As an adjective in English from 1580s.