4.2 Covalent Bonding Flashcards
Define covalent bonding?
The electrostatic attraction between protons in two nuclei and a shared pair of electrons between them
What is a group of atoms held together by covalent bonds called?
A simple molecules
What are in simple molecules?
Strong covalent bonds, and weak inter molecular forces
What happens to a simple molecular substance when it boils?
The weak intermolecular forces break
What happens when molecular mass increases?
The strength of weak intermolecular focus increasing, meaning a higher boiling point
Why do simple molecular substance not conduct electricity?
Molecules are neutral
What are examples of giant covalent substances?
- Diamond
- Graphite
- Silicon Dioxide
What are qualities of the structure of diamond?
- Every carbon atoms makes 4 covalent bonds
- Tetrahedral shape
- Strong, grid-like arrangement
Why does diamond and graphite sublime at very high temperatures?
- Covalent bonds are very strong
- Lots of bonds in the giant lattice
- Lots of energy is required to break all the bonds
What are qualities of the structure of graphite?
- Layers of hexagons of carbon atoms
- Every carbon atom makes 3 covalent bonds
- Weak IMFs between layers
- Delocalised electrons inside each layer
What are qualities of the structure of silicon dioxide?
- Every Si makes 4 covalent bonds
- Every oxygen makes 2 covalent bonds
- Tetrahedral shape
- Strong, grid-like arrangement
Why is silicon dioxide less expensive that diamond?
Much less rare
What is C60 Fullerene?
A unique simple molecule composed of 60 carbon atoms
Why is C60 Fullerene soft and slippery?
Because molecules can roll over each other easily
Why can’t diamond conduct electricity?
There are no freely moving particles. All the atoms are neutral and the electrons are stuck in an atom or bond
