Ancient Greek temple three steps, the "crepidoma". The uppermost level of the "crepidoma" provides the surface on which the columns and walls are placed; it is called stylobate. Placed on the stylobate are the vertical column shafts, tapering towards the top. They are normally made of several separately cut column drums. Depending on the architectural order, a different number of flutings are cut into the column shaft: Doric columns have 18 to 20 flutings, Ionic and Corinthian ones normally have 24. Early Ionic columns had up to 48 flutings. While Doric columns stand directly on the stylobate, Ionic and Corinthian ones possess a
Ionic compound for high-temperature solid-state synthesis. Many metals are geologically most abundant as ionic compounds within ores. To obtain the elemental materials, these ores are processed by smelting or electrolysis, in which redox reactions occur (often with a reducing agent such as carbon) such that the metal ions gain electrons to become neutral atoms. According to the nomenclature recommended by IUPAC, ionic compounds are named according to their composition, not their structure. In the most simple case of a binary ionic compound with no possible ambiguity about the charges and thus the stoichiometry, the common name is written using two words. The