Covalent Bonding Flashcards
Covalent Bond
A bond between two non-metals that is formed when a pair of electrons is shared between two atom
Simple molecular substances: bonding
Consists of just a few atoms joined together by strong covalent bonds
Intermolecular forces
Weak attractive forces between molecules
Simple molecular substances: melting & boiling points
Weak intermolecular forces so do not require a lot of heat energy to over come
Covalent bonds are not broken
Simple molecular substances: conductivity
Do not conduct electricity in any physical state because they do not contain electrons that are free to move
Some conduct when in solution because they dissolve in water (forming ions)
Simple molecular substances: solubility
Most are insoluble because the intermolecular forces between water and these substances are weaker than those between the water molecules and the molecules of the substance itself
Giant molecular substances
A giant molecule consisting of many atoms joined by covalent bonds, arranged in a lattice structure
Giant covalent structures: melting and boiling points
High melting and boiling points because strong covalent bonds that require a lot of heat energy to be broken
Examples of giant molecular stubstances
- Diamond
- Graphite
- Graphene
- C60 Fullerene
Diamond
- Each atom is bonded to four others
- Strong bonds between atoms
- High m+b points
- Does not conduct
Graphite
- Each atom is bonded to three others
- Weak intermolecular forces between layers
- Strong covalent bonds within layers
- High m+b points
- Conducts electricity (Non bonding electrons become delocalized so can move through the structure)
Graphene
- A single layer of graphite
- Each carbon is bonded to three other carbons
- High m+b points
- Conducts electricity (Non bonding electrons become delocalized so can move through the structure)
