Please enable JavaScript.
Coggle requires JavaScript to display documents.
Structure and Bonding - Coggle Diagram
Structure and Bonding
Ionic Bonding
Simple Ions form when atoms lose or gain an electron
1) Ions are charged particles - they can be
single atoms
or a
group of atoms
2)
Negative ions
(anions) form when atoms
gain electrons
- they have more electrons than protons
Positive ions
(cations) form when atoms
lose electrons
- they have more protons than electrons
3) The
number
of electrons lost or gained is the same as the
charge
on the ion. E.g. if 2 electrons are
lost
the charge is 2+. If 3 electrons are
gained
then the charge is 3-
You can
predict
the
ions
formed from the group number
1)
Groups 1,2 and 3 elements
are
metals.
They lose electrons to form
positive ions
2)
Group 5,6 and 7 elements
are
non-metals.
They
gain
electrons to form
negative ions
3) Elements in the same
group
all have the same number of electrons in their
outer shell.
So they can all
lose or gain
the same number of outer electrons. And this means that they form ions with the
same charge.
Some examples of tricky ions -
Ag+, H+, OH-
Transfer
of electrons produces
Ionic Compound
When a
metal
and a
non-metal
react together, such as when Group 1 metals react with Group 7 elements, the
metal atom loses
electrons to form a
positive ion
and the
non-metal gains these electrons
to form a
negative ion
These oppositely charged ions are
strongly attracted
to one another by
electrostatic attractions.
This attraction is called an
Ionic Bond
Covalent Bonding
Covalent substances
contain a
shared pair of electrons
1) Sometimes atoms make
covalent bonds
by
sharing
pairs of electrons with other atoms
2) Each
covalent bond
provides one
extra
shared electron for each atom
3) In covalent bonding, there's a strong
electrostatic attraction
between the negatively charged
shared electrons
(the bonding pair) and the positively charged
nuclei
of the atoms involved