Neon is a noble gas (inert), which means it will not react with other atoms because of its full outer shell (see octet rule). It does not 'need' to react with other atoms in order to.
Ionic radius, r ion, is the radius of a monatomic ion in an ionic crystal structure. 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.Ionic radii are typically given in units of either picometers (pm).
A negatively charged ion, as one attracted to the anode in electrolysis. Any negatively charged atom or group of atoms (opposed to cation).
Cations and anions are both ions. The difference between a cation and an anion is the net electrical charge of the ion. Ions are atoms or molecules which have gained or lost one or more valence electrons, giving the ion a net positive or negative charge. If the chemical species has more protons than electrons, it carries a net positive charge.

Ne Cation Or Anion