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.
Mosaic has a long history, starting in Mesopotamia in the 3rd millennium BC. Pebble mosaics were made in Tiryns in Mycenean Greece; mosaics with patterns and pictures became widespread in classical times, both in Ancient Greece and Ancient Rome.