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.
IONIC BOND. The ionic bond is the electrostatic force of attraction between two oppositely charged ions i.e., a positively charged cation and a negatively charged anion. It is formed due to complete transfer of electrons from one atom to another atom. The steps involved in the formation of ionic bond can be summarized as: 1  a) An electropositive atom (metal) loses electron(s) to form a positively charged ion called as cation. 2  b) An electronegative atom accepts the electron(s) to form a negatively charged ion, otherwise known as anion.