Simple molecular substances:
- Form very strong covalent bonds to form small molecules
- Force of attraction is very weak between the molecules
- Most are gases or liquids at room temperature
DIAMOND
1 carbon = 4 covalent bonds forming a very hard and rigid structure
GRAPHITE
1 carbon = 3 covalent bonds forming layers that are free to slide over eachother. The layers are loose so they can be rubbed off. Leaves free electrons - graphite is the only non-metal which is a good conductor of electricity
SILICA
Each grain of sand is one giant struture of silicon and oxygen, it can be melted down with sodium carbonate and limestone to make glass.
Giant covalent structures:
- NO CHARGED IONS
- Have very strong covalent bonds
- Very high melting and boiling points
- Don't conduct electricity, even when molten
- Usually insoluble
Comments
No comments have yet been made