Zusammenfassung der Ressource
Lvl 2 Chem: Types of
Substances
- Metallic
- Forces Between
Particles
- Strong electrostatic forces of
attraction between the
electrons and positive nuclei
of metal atoms
- Properties
- Conducts
electricity
- They have free electrons that
are able to move and hence
conduct a charge
- Insoluble
in water
- The electrostatic
forces between the
particles are too
strong to be
overcome by the
attractive forces
between water and
the metal
- Malleable and
Ductile
- The non-directional
attraction of the valence
electrons means that metal
atoms can slide past each
other without breaking the
overall structure
- High melting
and boiling
point
- There are strong
electrostatic forces
which require lots of
energy to overcome
- Structure
- Free electrons from
outer shell of metal
atoms alternate with
positive metal ions
- Particles
- Positive
nuclei and delocalised
electrons
- Covalent Network
- Properties
- Do not
conduct
electroicty
- They have no free
electrons or ions
- Usually
Insoluble
in water
- Many molecular substances are not
polar, since water is polar and like
dissolves like, only polar substances
will dissolve in water. Polarity is
decided by the shape of the molecule
(see structure)
- Low melting and
boiling point
- The weak
intermolecular
forces do not
require a lot of
energy to overcome
- Forces
Between
Particles
- Weak intermolecular forces of
attraction between the molecules
- Particles
- Molecules made up of atoms
(strong intramolecular covalent
bonds between these atoms)
- Structure
- 2 Regions of
negative
charge
- Linear
- 4 regions
of negative
charge
- Two bonded,
two non-bonded
- Bent 4:
- All bonded
- Tetrahedral
- Three bonded,
one non-bonded
- Trigonal Planer
- 3 regions of
negative charge
- All bonded
- Trigonal Planar
- Two bonded, one
non-bonded
- Bent 3
- Molecular
- Particles
- Atoms
- Structure
- 2D
- 2D hexagonal layers. Within each
layer the atom is bonded to three
others, with delocalised electrons
between the layers
- 3D
- 3D lattice where each atom is bonded
to 4 others by strong covalent bonds.
- Forces Between
Particles
- Strong covalent bonds
between atoms
- Properties
- Graphite is soft
- Layers are held together by
weak bonds so can slide
past each other
- Diamond is
hard
- Strong covalent bonds makes the
structure very rigid
- High melting
and boiling
point
- Strong covalent bonds so require
lots of energy to overcome.
- Diamond does not
conduct, but
graphite does.
- Diamond does not have free
electrons so does not conduct
whereas graphite does
- Ionic
- Forces Between
Particles
- Strong electrostatic forces of
attraction between oppositely
charged ions
- Structure
- Regular 3D lattice structure
consisting of alternating
cations and anions
- Particles
- Negatively charged
anions and
positively charged
cations
- Properties
- Conduct when
molten or in
solution
- Electrons are removed from the
rigid structure so can move and
carry a charge
- High melting
and boiling
points
- Strong electrostatic forces of
attraction so require large
amounts of energy to
overcome
- Dissolve in
polar solvents
- The cations are attracted to
the negative dipole whilst the
anions are attracted to the
positive dipole
- Do not conduct in
solid form
- Electrons are fixed in the 3D
lattice so cannot move or carry a
charge