Classification of Structures

Classification of Structures

Simple Molecular Structure

• Simple molecular structures are made up of small molecules.
• The molecules are made up of a few atoms joined together by covalent bonds.
• Examples of simple molecular structures include oxygen (O2), methane (CH4), and water (H2O).

Giant Covalent Structure

• This structure consists of a vast number of atoms covalently bonded together, creating a large crystalline lattice.
• Giant covalent structure substances are held together by numerous strong bonds, which give them high melting and boiling points.
• Examples include diamond, silicon dioxide and graphite. Each atom in these structures is connected to other atoms by strong covalent bonds.

Macroscopic Structures

• These are structures on a scale large enough to be visible to the naked eye or under a microscope.
• Examples include metals, ceramics, and polymers which form crystalline lattices or amorphous structures at a macroscopic scale.

Ionic Structure

• An ionic structure is a giant structure of ions.
• The ions have a regular, repeating arrangement called an ionic lattice.
• The lattice is formed because the ions attract each other and form a regular pattern with ions of opposite charge next to each other.
• Sodium chloride (NaCl) is an example of an ionic structure.

Metallic Structure

• A metallic structure consists of a regular array of positively charged ions, with the outer shell (delocalised) electrons free to move.
• The sea of free-moving delocalised electrons gives metallic substances their unique properties, such as electrical and thermal conductivity.
• Alloys are examples of metallic structure substances.