Chemistry-Chemical Bonding

Metallic bonding
-Metallic atoms are bonded together.
-Metal atoms lose their outer valence electrons and become positively charged in a metal lattice.
-These electrons which now do not belong to any metal atom are called 'delocalised'.
-The definition of a metallic bond is 'The force of attraction between positive metal ions and the free electrons'.

Key words concerning metallic bonding
-Delocalised
-Metallic bond
-Positive metal ions
-Sea of free electrons
-High boiling and melting points
-Lattice
-Force of attraction

Diagrams that effectively show metallic bonding

-Conduct heat, electricity

-Generally high melting and boiling points

-Strong

-Malleable

-Ductile

-Metallic lustre

-Opaque

-Insoluble

Covalent compounds	Ionic compounds	Metallic compounds
Formed between non-metals (generally)	Formed between metals and non-metals (generally)	Formed between metals
Low melting point, boiling point	High melting point, boiling point	High melting point, boiling point
Sharing pairs of electrons to obtain octet/ duplet structure	Gaining/Losing electrons to obtain octet/ duplet structure	Attraction between metal cation and shared electrons around it in a sea of delocalised electrons
Does not conduct electricity (generally)	Conduct electricity when dissolved in water	Conduct electricity in liquids
Insoluble in water	Soluble in water	Insoluble in water

Covalent compounds
Simple molecular structure
Giant molecular structure (e.g. diamond, sand ; high BP and MP
Low BP and MP: Bonding is weak as there are weak intermolecular forces. Little energy is needed to break the bonding, making the BP and MP low as less heat is needed to break the bonds.
Does not conduct electricity: There are no delocalised electrons as electrons are shared between the atoms.
Insoluble in water: Water is a polar solvent. Most covalent compounds are non-polar solvent. Hence, they do not dissolve in water.

Ionic compounds
Giant lattice structure
High BP and MP: Ions held together by strong electrostatic force. More heat is required to overcome this force, causing the BP and MP to be high.
Conduct electricity when dissolved in water: When ionic compounds dissolve, water break to their cations and anions. These delocalised ions allow the conducting of electricity.
Soluble in water: Water is a polar solvent. Water molecules surround the ionic compound when it is in water, giving enough energy to separate the ionic bond and allow the ionic compound to dissolve in water.

Metallic compounds
Giant lattice structure
High BP and MP: Metallic bonds (electrostatic forces of attraction)are very strong. Hence, more heat is needed to overcome the bonding, making the BP and MP higher.
Conduct electricity in liquids: In liquid, electrons in metallic bonds delocalised and allows the conducting of electricity.
Insoluble in water: They are insoluble in water unless they undergo a chemical reaction with it.