Ionic order a version of such a perfectly four-sided Ionic capital; Scamozzi's version became so much the standard, that when a Greek Ionic order was eventually reintroduced, in the later 18th century Greek Revival, it conveyed an air of archaic freshness and primitive, perhaps even republican, vitality. The Ionic column is always more slender than the Doric; therefore, it always has a base: Ionic columns are eight and nine column-diameters tall, and even more in the Antebellum colonnades of late American Greek revival plantation houses. Ionic columns are most often fluted. After a little early experimentation, the number of hollow flutes in
Ionic compound usually in a crystalline structure. Ionic compounds containing hydrogen ions (H) are classified as acids, and those containing basic ions hydroxide (OH) or oxide (O) are classified as bases. Ionic compounds without these ions are also known as salts and can be formed by acid–base reactions. Ionic compounds can also be produced from their constituent ions by evaporation of their solvent, precipitation, freezing, a solid-state reaction, or the electron transfer reaction of reactive metals with reactive non-metals, such as halogen gases. Ionic compounds typically have high melting and boiling points, and are hard and brittle. As solids they are almost