Ionic order Ionian dialect was spoken. The Ionic order column was being practiced in mainland Greece in the 5th century BC. It was most popular in the Archaic Period (750–480 BC) in Ionia. The first of the great Ionic temples was the Temple of Hera on Samos, built about 570–560 BC by the architect Rhoikos. It stood for only a decade before it was leveled by an earthquake. A longer-lasting 6th century Ionic temple was the Temple of Artemis at Ephesus, one of the Seven Wonders of the Ancient World. The Parthenon, although it conforms mainly to the Doric order, also has
Ionic compound and negative ions must be maintained. Instead the material undergoes fracture via cleavage. As the temperature is elevated (usually close to the melting point) a ductile–brittle transition occurs, and plastic flow becomes possible by the motion of dislocations. The compressibility of an ionic compound is strongly determined by its structure, and in particular the coordination number. For example, halides with the caesium chloride structure (coordination number 8) are less compressible than those with the sodium chloride structure (coordination number 6), and less again than those with a coordination number of 4. When ionic compounds dissolve, the individual ions dissociate and