Question

Draw electron dot structure for the formation of magnesium oxide.

Answer 1

Part 1: Electron dot structure:

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

Part 2: 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.

Part 3: Formation of Magnesium oxide ($\mathrm{MgO}$) by the transfer of electrons:

Magnesium Oxide($\mathrm{MgO}$) is the most chemically active element. Magnesium is the central atom with an atomic number is 12, placed in the 2^nd group 2 and 3^rd period in the modern periodic table.

When magnesium reacts with oxygen, the magnesium atom transfers its two outermost electrons to an oxygen atom. By losing two electrons, the magnesium atoms form a magnesium ion (${\mathrm{Mg}}^{2+}$) and by gaining two electrons, the oxygen atom forms an oxide ion (${\mathrm{O}}^{2-}$).