Zusammenfassung der Ressource
Structures of Materials
- Simple molecular substances
- Low melting and
boiling points
- Above 20 degrees=
solid Below 20
degrees= gas
- Cannot conduct electricity
- Non-metals
- Because the molecules are small, the
intermolecular forces are weak.
- Can be both elements and compounds
- Only a few atoms held together by
strong covalent bonds.
- Giant Covalent
- Bonds are formed by electron pairs shared between
atoms. The positively charged nuclei of both atoms
are attracted to the negatively charged shared
electrons. This is a covalent bond.
- High melting points
- Atoms are usually arranged into giant
regular lattices.
- Variable conductivity
- Diamond
- A form of carbon in which
each carbon atom is joined
to four other carbon atoms.
- Very hard
- High melting point
- Non-conductor of electricity
- Graphite
- Form of carbon in which the carbon
atoms form layers. These layers can
slide over each other.
- Much softer than diamond
- Conducts electricity
- Giant Ionic
- Have a crystal lattice structure.
This is a regular pattern of rows
and columns.
- Giant ionic lattice- the regular 3D pattern
is repeated over and over again in all
directions.
- Made up of positively and
negatively charged ions.
- Ionic bonds are the electrostatic
forces of attraction between
oppositely charged ions.
- High melting and boiling points
- A lot of energy is required
to overcome the attractive
forces.
- Conducts electricity in the liquid
state or when dissolved in water.