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 atomic radius of Br is smaller than the ionic radius of Br- The atomic radius of Br is the smallest of the atoms in the fourth period besides Kypton. The radius of the electron density shell remains the same but the number of protons creating a pull increases. The ionic radius of Br- is larger than the atomic radius of Br because there is one more electron but no more protons. For additional help: Atomic radius starts at 6:00 and and ionic radius at 7:12.