Describe the formation of
ions by electron loss or
gain
If an atom contains more electrons than protons the
atom has a negative charge. If the atom contains
fewer electrons than the protons the atom has a
positive charge. Ions are a group of atoms that carry
a positive or negative charge.
Describe the formation of
ionic bonds between
elements from Groups I
and VII
Explain the formation of
ionic bonds between
metallic and non-metallic
elements
Ionic bonds are the bonds that form between
opposite charges. A metal reacts with non-metal
to form an ionic-compound.The metal ions lose
electron. The non-metal gain them. The ions
form a lattice. The compound has no over all
charge.
State that non-metallic
elements form non-ionic
compounds using a
different type of bonding
called covalent bonding
Same nuclei attract the shared
electrons -this a strong force of
attraction hold the 2 atoms
together. The force of attraction is
called covalent bonds.
Draw dot and cross diagrams
to represent the sharing of
electron pairs to form single
covalent bonds
Single bonds
Draw dot and cross
diagrams to represent
the multiple bonding
Describe the differences in volatility,
solubility and electrical conductivity
between ionic and covalent compounds
Volatility
Ionic bonds have
high melting and
boiling points.
Covalent bonds have
low melting and boiling
points.
Solubility
Ionic bonds tend to
be soluble in water.
Covalent bonds tend to be
insoluble.
Electrical
Conductivity
Ionic bonds conduct
electricity when melted
or dissolved in water.
Covalent bonds do
not conduct
electricity.
Describe the giant
covalent structures of
graphite and
diamond
Graphite
~Each carbon attached to three other carbon atoms
~Hexagonal ring layered lattice structure
~Delocalised electrons within each layer
~Weak intermolecular forces between the layers.
Daimond
~Each carbon forms four covalent bonds with other carbon atoms
~Each carbon has a tetrahedral arrangement
~All electrons are localised in covalent bonds.
Relate their structures to the
use of graphite as a lubricant
and of diamond in cutting
DIamond
~Each atom is held place by 4
strong covalent bonds. It has a
high melting point.It also cannot
conduct electricity.
Graphite
~Each atom is held in place by
3 strong covalent bonds. It
has a low melting points. It
also can conduct electricity.
Describe the structure
of silicon(IV) oxide
(silicon dioxide)
Silicon is similar to diamond. Each silicon atom
bonds covalently with 4 oxygen atoms. Each
oxygen atoms bonds covalently with 4 silicon
atoms and the result is a very hard matarial with
a high melting point.