1.39: Write Formulae for Compounds Formed Between the Ions Listed Above

IONIC COMPOUNDS: Formed when Atoms of Metals transfer Electrons to atoms of Non - Metals to form Compounds made up of ions

FORMULAE FOR COMPOUNDS FORMED BETWEEN IONS

• METALS: Loses Electrons to another atom and become Positively Charged Ions
• NON - METALS: Gains Electrons from another atom to become Negatively Charged Ions

Example 1:

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Sodium Chloride, NaCl (typical Ionic Bond)

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SODIUM ATOM Sodium is a Group 1 Metal so will need to lose one outer Electron to another Atom to have a full outer shell of Electrons They will lose an Electron to form a Positive ion with the Charge 1+ (as they lose one outer electron)           Na   2 . 8 . 1      →      Na+   2 . 8 CHLORINE ATOM Chlorine is a Group 7 Non-Metal so will need to gain an Electron to have a full outer shell of Electrons One Electron will be transferred from the outer shell of the Sodium atom to the outer shell of the Chlorine atom Chlorine atom will gain an Electron to form a Negative ion with Charge 1- (as they gain an outer electron)           Cl   2 . 8 . 7      →      Cl-   2 . 8 . 8 FORMULAE OF IONIC COMPOUND:    NaCl

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Example 2:

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Magnesium Oxide, MgO (typical Ionic Bond)

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MAGNESIUM ATOM Magnesium is a Group 2 Metal so will need to lose two outer Electrons to another atom to have a full outer shell of Electrons They will lose two Electrons to form a Positive Ion with the Charge 2+ (as they lose two outer electrons)           Mg   2 . 8 . 2      →      Mg2+   2 . 8 OXYGEN ATOM Oxygen is a Group 6 Non-Metal so will need to gain two Electrons to have a full outer shell of Electrons Two Electrons will be transferred from the outer shell of the Magnesium atom to the outer shell of the Oxygen atom Oxygen atom will gain two Electrons to form a Negative ion with Charge 2- (as they gain two outer electrons)           O2   2 . 8 . 6      →      O22-   2 . 8 . 8 FORMULAE OF IONIC COMPOUND:    MgO