2.6 Giant covalent structures Flashcards
What is the structure of diamond?
In diamond, each carbon atom is covalently bonded to 4 other carbon atoms, forming a tetrahedral 3D structure.
What are the properties of diamond?
Diamond is very hard, has a high melting and boiling point, cannot conduct electricity, and has a rigid structure due to strong covalent bonds.
Why is diamond used in cutting tools?
Diamond is very hard due to its rigid structure held together by strong covalent bonds, making it ideal for cutting tools.
What is the structure of graphite?
In graphite, each carbon atom is covalently bonded to 3 other carbon atoms, forming layers of hexagonal rings. There are weak intermolecular forces between the layers.
What are the properties of graphite?
Graphite is soft (due to weak intermolecular forces between layers), conducts electricity (because of delocalised electrons), and has high melting and boiling points.
Why is graphite used as a lubricant and an electrode?
Graphite’s layers can slide over each other, making it a good lubricant. It can also conduct electricity due to delocalised electrons, making it useful as an electrode in electrolysis.
What is the structure of silicon(IV) oxide (SiO2)?
In silicon dioxide (SiO2), each silicon atom is covalently bonded to 4 oxygen atoms, and each oxygen atom is bonded to 2 silicon atoms.
What are the properties of silicon(IV) oxide?
Silicon(IV) oxide has a hard structure, a high melting and boiling point, and does not conduct electricity. It has a rigid tetrahedral arrangement like diamond.
What is the similarity in properties between diamond and silicon(IV) oxide?
Both diamond and silicon(IV) oxide have a tetrahedral structure and strong covalent bonds, giving them high melting points, hardness, and rigidity.
What is a giant covalent (macromolecular) structure?
A giant covalent structure is a solid with very high melting points, where all the atoms are covalently bonded in a giant network.
