Covalent compounds - structures and properties - Giant Macromolecular Covalent (Second type) Flashcards
All the atoms are bonded to each other by…
very strong covalent bonds.
Give 3 examples
Diamond (type of carbon), Graphite (type of carbon), Silicon Dioxide …
Describe the structure of Diamond
Diamond is a giant covalent compound, made of carbon atoms and each one is connected to four others by strong covalent bonds forming a giant structure.
Why does Diamond have such a high melting and boiling point?
A high temperature (large energy) is required to melt diamond as diamond is a giant covalent structure made of carbon atoms and each one is connected to four others by very strong covalent bonds. All these bonds must be broken.
Why do covalent compounds not conduct electricity (except graphite)?
As there are no free (delocalised) electrons (or free ions).
Why does graphite conduct electricity?
Graphite is giant covalent compound in which each atom is bonded to three other carbon atoms, this leaves free (delocalised) electrons, allowing it to be a good conductor.
Why is graphite ‘crumbly’ or soft?
Graphite is a giant covalent compound in which each carbon atom is bonded to only 3 other carbon atoms, causing it to form layers held together by weak forces. The layers can slide over each other and break away easily.
