Question

Draw electron dot representation for the formation of sodium oxide.

Answer 1

Electron dot structure:

It defines the nature of bond and position of atoms of the molecule which are connected in the molecule. The structure will also display the total number of lone pairs present in each of the atoms that constitute the molecule.

The steps that must be followed while drawing a Lewis structure are listed below:

• First, the total number of valence electrons present in the molecule is calculated by adding the individual valencies of each atom.
• If the molecule is an anion, extra electrons (number of electrons added = the magnitude of negative charge) are added to the Lewis dot structure.
• When cationic molecules are considered, electrons are subtracted from the total count in order to make up for the positive charge.
• The least electronegative atom is made the central atom of the molecule or ion.
• The atoms are now connected via single bonds.
• Now, the lone pairs of electrons are assigned to each atom belonging to the molecule. Commonly, the lone pairs are assigned to the most electronegative atoms first.
• Once the lone pairs are assigned, if every atom does not have an octet configuration, a double or triple bond must be drawn to satisfy the octet valency of each atom.
• If required, a lone pair can be converted into a bond pair in order to satisfy the octet rule for two atoms.

Formation of Sodium oxide:

Two sodium atoms transfer their 2 outermost electrons to an oxygen atom. By losing two electrons, the two sodium atoms form sodium ions ($2{\mathrm{Na}}^{+}$) and by gaining two electrons, the oxygen atom forms an oxide ion (${\mathrm{O}}^{2-}$).