Science with Tara

Chemical bonding determines the structure and properties of substances. There are four main types of structures in Chemistry:

Ionic Structure (Giant Ionic Lattice)

Formed between metallic atoms and non-metallic atoms by transfer of electrons.

Metallic atoms form positive ions (cations) while non-metallic atoms form negative ions (anions).

Ionic compounds form giant ionic lattice structure.

Oppositely charged ions are held together by strong electrostatic forces of attraction in the giant lattice structure.

Examples: Sodium chloride (NaCl), Lithium fluoride (LiF), Calcium oxide (CaO)

Simple molecular structure

Formed between non-metallic atoms by sharing of electrons (covalent bonding).

One simple molecule is made of a few atoms joined together by strong covalent bonds within molecule.

Weak intermolecular forces of attraction exist between molecules.

When melted or boiled, heat energy overcome weak intermolecular forces of attraction between simple molecules.

Note: The covalent bonds are not broken.

Examples: Hydrogen (H₂), Oxygen (O₂), Hydrogen chloride (HCl), Water (H₂O)

Metallic Structure (Giant Metallic Lattice)

Formed between metallic atoms where each metallic atom loses electrons to become positive ions. The delocalised electrons go into the spaces between the
positive ions.

Metals have giant metallic structure consisting of a lattice of positive ions in a sea of delocalised electrons.

Examples: All metals (e.g. Iron, Copper, Sodium, Aluminium)

Giant molecular structure

Formed between non-metallic atoms by sharing of electrons. One giant molecule is made of a giant network of atoms joined together by strong covalent bonds.

Macromolecules have giant molecular structure. A giant network of atoms are covalently bonded together.

Examples: Carbon (graphite), Carbon (diamond), Silicon dioxide (SiO₂ / sand)

Comparison Table

Structure Type	Particles Present	Bonding / Forces	Examples
Ionic (Giant Ionic)	Positive & negative ions	Strong electrostatic forces	NaCl, CaO
Simple Molecular	Small molecules	Weak intermolecular forces	H₂, H₂O, HCl
Metallic	Positive ions + delocalised electrons	Metallic bonding (strong)	Fe, Cu, Al
Giant Molecular	Giant network of atoms	Strong covalent bonds throughout	Diamond, Graphite, SiO₂