Princeton's WordNet(0.00 / 0 votes)Rate this definition: geological time, geologic time(noun) the time of the physical formation and development of the earth (especially prior to human history)
Ionic radius, r ion, is the radius of an atom's ion.Although neither atoms nor ions have sharp boundaries, they are sometimes treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice.herefore, the distance between the Na + and Cl â ions is half of 564.02 pm, which is 282.01 pm. However, although X-ray crystallography gives the distance between ions, it doesn't indicate where the boundary is between those ions, so it doesn't directly give ionic radii.
The structure of a typical ionic solid - sodium chloride. How the ions are arranged in sodium chloride. Sodium chloride is taken as a typical ionic compound. Compounds like this consist of a giant (endlessly repeating) lattice of ions. So sodium chloride (and any other ionic compound) is described as having a giant ionic structure. You should be clear that giant in this context doesn't just mean very large.