Why is ionic bonding referred to as non directional?

is non-directional because an ion has the same attraction from all directions for an ion of opposite charge.

In the same way, a magnet attracts iron filings from all directions.
This means that packing efficiency in the crystal lattice determines the arrangement of ions in a crystal.
There is no preferred direction for the bonds.
Thus, in a crystal of ##”NaCl”##, a sodium ion has 6 chloride ions as nearest neighbours.
The ##”Na-Cl”## “bonds” are all at angles of 90° to each other.

In a crystal of cesium chloride, a cesium ion has eight chloride atoms as nearest neighbours.
The ##”Cs-Cl”## “bonds” are at different angles.
The differences arise because ##”Cs”^”+”## and ##”Cl”^”-“## have almost the same ionic radii (about 170 pm) and pack in one arrangement.
A ##”Na”^”+”## ion is smaller (116 pm) than ##”Cl”^”-“##, so the ions pack in a different arrangement.

Posted in Uncategorized

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>