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 bonding cannot exist, as the proximity of the entities involved in the bonding allows some degree of sharing electron density between them. Therefore, all ionic bonding has some covalent character. Thus, bonding is considered ionic where the ionic character is greater than the covalent character. The larger the difference in electronegativity between the two types of atoms involved in the bonding, the more ionic (polar) it is. Bonds with partially ionic and partially covalent character are called polar covalent bonds. For example, Na–Cl and Mg–O interactions have a few percent covalency, while Si–O bonds are usually ~50% ionic and ~50% covalent.