4.1 Covalent bonding Flashcards
(12 cards)
Covalent bonding definition
The electrostatic attraction between protons in two nuclei and a shared pair of electrons between them
covelant bonding strength
very strong
what are a group of atoms held together by covalent bonds called
simple molecules
simple molecular substances - boiling points
Low boiling points - even though they have very strong covalent bonds, there are weak intermolecular forces between molecules
as molecular mass increases so does the strength of the weak intermolecular forces, meaning the boiling point increases
electrical conductivity of simple molecular substances
they never conduct electricity as there are no charged particles that are free to move
what is C60 fullerene
a unique simple molecule composed of 60 carbon atoms in a ball
Boiling/melting point of C60 fullerene
low - weak forces - easily broken
Diamond properties
- very high melting/boiling point - strong covalent bonds - lots of bonds in the giant ionic lattice - lots of energy required to break these bonds
Graphite properties
- very high melting/boiling point (same reasons as diamond)
- soft and slippery as it has layers which can slide easily
- weak IMFs between layers
- conducts electricity - delocalised electrons free to move and carry charge
graphite uses
solid lubricant
diamond uses
cutting
silicon dioxide
similar properties to diamond
