Covalent bonding Flashcards
What is a covalent bond?
Strong electrostatic attraction between a shared pair of electrons and the positive nuclei
What type of elements form covalent bonds?
non-metals
Give the displayed formula of H₂O
H-O-H
Give the displayed formula of O₂
O=O
What is a single covalent bond
single pair
What is a double covalent bond?
two pairs
What is a simple molecular substance?
A simple molecular substance is a covalent molecule made up of just a few atoms
What is the melting point of a simple molecular substance and why?
low because weak intermolecular forces do not require a lot of energy to overcome
What is the conductivity of a simple molecular substance?
do not conduct electricity as no ions or delocalised electrons that can move
What is the solubility of a simple molecular substance?
usually insoluble in water as simple molecules are not attracted to water
What is a Buckminster fullerene?
(C₆₀) simple molecule composed of 60 carbon atoms in a ball
What is the boiling point in a Buckminster fullerene?
600ºC
low compared with giant covalent structures due to weak intermolecular forces which don’t require a lot of energy to overcome
high compared with other simple molecular substances as there are more electrons in the molecule
Why is a Buckminster fullerene soft and slippery?
weak intermolecular forces that can move
What is a giant covalent substance?
Structures containing a large number of non-metal atoms each joined to adjacent atoms by covalent bonds.
Give three examples of giant covalent substances
Diamond (each carbon atom bonded to 4 others), silicon dioxide, graphite (each carbon atom bonded to 3 others)