(i) Write the electron-dot structures for sodium and oxygen. (ii) Show the formation of Na2O and MgO by the transfer of electrons. (iii) What are the ions present in these compounds?

Solution: (i) Sodium:

Oxygen:

(ii) Formation of Magnesium oxide:

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 (Mg²⁺), and by gaining two electrons, the oxygen atom forms an oxide ion (O^2-).

Mg: +
→ MgO

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 (2Na⁺). And by gaining two electrons, the oxygen atom forms an oxide ion (O^2-).

(iii) The ions present in sodium oxide compound (Na₂O) are sodium ions (2Na⁺) and oxide ions (O^2-).

The ions present in Magnesium oxide compound (MgO) are magnesium ions Mg²⁺ and oxide ions (O^2-).