(i) Write the electron-dot structures for sodium, oxygen and magnesium. Show the formation of Na 2 O and MgO by the transfer of electrons.
The two sodium atoms lose 1 electron each to form 2 sodium ions (2Na + ).
The oxygen atom forms an oxide ion (O 2- ) by gaining 2 electrons, one from each sodium atom.
Na and O hence form an ionic compound Sodium Oxide (Na 2 O).