Study Notes
Giant covalent structures are large networks of atoms bonded by covalent bonds, resulting in unique properties. Diamond — a form of carbon where each atom is bonded to four others, making it very hard and a poor conductor of electricity.
Example: Used in cutting tools due to its hardness.
Graphite — a form of carbon where each atom is bonded to three others, forming layers that can slide over each other, making it soft and a good conductor of electricity.
Example: Used as a lubricant and in electrodes.
Silicon Dioxide (SiO2) — each oxygen atom is bonded to two silicon atoms, and each silicon atom is bonded to four oxygen atoms.
Example: Used in foods and supplements.
Exam Tips
Key Definitions to Remember
- Giant covalent structures: Large networks of atoms bonded by covalent bonds.
- Diamond: Carbon atoms bonded to four others, very hard.
- Graphite: Carbon atoms bonded to three others, forms layers.
- Silicon Dioxide: Oxygen atoms bonded to two silicon atoms.
Common Confusions
- Confusing hardness with strength; diamond is hard but brittle.
- Mistaking pencil lead for metal lead; pencil lead is graphite.
Typical Exam Questions
- What is the structure of diamond? Each carbon atom is bonded to four others, forming a rigid structure.
- Why is graphite used as a lubricant? Because its layers can slide over each other.
- How does silicon dioxide's structure relate to its properties? Its strong covalent bonds make it hard and durable.
What Examiners Usually Test
- Differences in bonding and properties between diamond and graphite.
- Uses of graphite and diamond based on their structures.
- Similarities between diamond and silicon dioxide structures.