9. IONIC TYPE OF THE CHEMICAL BOND.

Purely ionic bond is called chemically connected condition of atoms at which steady electronic environment is reached by full transition of the general electron density to atom of more electronegative element.
In practice full electron transition from one atom to other atom-pareneru on communication is not implemented as each element has big or smaller, but not zero, electronegativity, ilyuby communication will be somewhat covalent.
The ionic bond is possible only between atoms of the electropositive and electronegative elements which are in condition raznoimenno of the loaded ions.
Ions are electrically the charged particles which are formed of neutral atoms or molecules by return or accession of electrons. At return of electrons the positively charged ion cation is formed, at accession - negative-anion.
At return or accession of electrons molecules form molecular or polyatomic ions, for example ^O2+ - cation of dioksigenil, ^NO2-nitrite ion.
One-atomic cations and one-atomic anions arise at chemical reaction between neytralna atoms by mutually electron transfer. At the same time the atom of electropositive element possessing small number of external electrons passes into more stable state of one-atomic cation by reduction of number of these electrons. On the contrary, the atom of electronegative element having large number of electron on external layer passes into condition of one-atomic ion, steadier for it, by increase in number of electrons.
One-atomic cations are formed, as a rule, by metals, and one-atomic anions-nonmetals. At electron transfer of metal and nonmetallic elements aim to create steady configuration of electron shell around the kernels. Atom of non-metallic element creates external cover of the subsequent rare gas whereas atom of metal element after return of external electrons receives steady configuration of the previous rare gas.

Scheme of ionic bonding.

The Coulomb forces of attraction arising at interaction of the loaded ions strong also work equally in all directions. As a result of it the arrangement of ions is arranged in space definitely, forming ionic crystal lattice. Substances from ionic KR at usual conditions are in crystalline state, they have high melting temperatures and boilings.

 

 

  

 

---

9

---