Explain the ionic bond formation in `MgO and CaF_(2)` :

Explanation

Electronic configuration of `Mg -1s^(2)" "2s^(2)" "2p^(6)" "3s^(2)" "3s^(2)`
Electronic configuration of `O - 1s^(2)" " 2s^(2)" "2p^(6)" "3s^(2)" "3p^(4)`
(i) Magnesium has two electrons in its valence shell and oxygen has sIx electrons in its valence shell.
(ii) By losing two electrons, Mg acquires the inert gas configuration of Neon and becomes a dipositive cation, `Mg^(2+)`:
`MgrarrMg^(2+)+2e^(-)`
Oxygen accepts the two electrons to become a dinegative oxide anion, `O^(2-)` thereby attaining the inert gas configuration of Neon: `O + 2e^(-) rarr O^(2-)`
(iv) These two ions, `Mg^(2+) and O^(2-)` combine to form an ionic crystal in which they are held together by electrostatic attractive forces.
(v) During the formation of magnesium oxide crystal 601.6 kJ `mol^(-1)` energy is released. This Tavours the formation of magnesium oxide (MgO) and its stabilisation.
`CaF_(2),` Calcium fluoride
Calcium. Ca : [Ar] `4s^(2)`
Fluorine, F: [He] `2s^(2)" "2p^(5)`
(ii) alcium has two electrons in its valence shell and fluorine has seven electrons in its valence shell.
(iii) By losing two clectrons, calcium attains the inert gas configuration of Argon and becomes a dipositive cation, `Ca^(2+)`
(iv) Two tiuorine atoms, each one accepts one electron to become two uninegative fluoride ions `(F^(-))` thereby attaining the stable configuration of Neon.
(v) These three ions combine to form an ionic crystal in which they are held together by electrostatic attractive force.
(iv) During the formation of calcium fluoride crystal 1225.91 kJ `mol^(-1)` of energy is released.
This favours the formation of calcium fluoride. `CaF_(2)` and its stabilisation.