11. • a collection of atoms or molecules that are held
together so that, under constant conditions, they
maintain a defined shape and size
• formed when the temperature of a liquid is low and
the pressure is sufficiently high causing the particles to
come very close to one another
• are not necessarily permanent
• rigid
• particles hardly diffuse
SOLID
13. Electricity is essentially a
flow of electrons from
one place to another,
and in metallic bonds the
outer electrons are
relatively free to move
between adjacent atoms.
This electron mobility
means it is easy for an
electrical current to
move from one end of a
piece of metal to the
other.
14. Materials that do not
conduct electricity are
called electrical
insulators. Insulators
have electrons that are
engaged in a covalent or
ionic bond and therefore
are not able to conduct
electricity, or do so only
poorly.
15. • Metals are also good conductors of heat
• Consider that temperature is a measurement of how much molecules
are moving.
16. In a network solid, such transfer is more difficult.
Such solids would be expected to have low
conductivity and would be called heat insulators.
17. GRAPHITE
• A shiny black substance that
is used in pencils
• It is an allotrope of carbon.
• The only non-metal that
conducts heat and
electricity.
22. A solid’s melting point depends on the
strength of the interactions between its
components.
For molecular solids, melting means breaking
the weak intermolecular forces, not the strong
covalent bonds that hold the individual
molecules together.
25. SOLUBILITY
Is the ability to dissolve the solid into some
type of liquid.
The solid which we refer as “Solute” and the
liquid that do the dissolving is called “Solvent”
27. DISSOLVING A SOLID REQUIRES
BREAKING DIFFERENT TYPES OF
BONDS FOR DIFFERENT TYPES OF
SOLIDS
Dissolving a metal requires breaking metallic bonds, and
dissolving a network solid requires breaking covalent bonds. Both
of these types of bonds are strong.
Molecular solids, however, requires breaking only weak
intermolecular forces, not the covalent bonds that actually hold
the individuals together.
30. In other words, density is how close together the molecules of a
substance are or how much mass a substance has in a given space.
31. Now that we know about the properties
of solid, we can now conclude that the
interparticle forces are responsible for
these properties and the behaviour of
particles.