Chemical bonds.
The interactions of 2
or more atoms mainly
occur at the outermost
shell, or energy level.
The consequence of these interactions
results in a chemical reaction.
In atoms that have fewer or more than 8
electrons in their outermost energy level,
reactions occur that result
in the loss, gain, or sharing
of electrons with another atom
to satisfy the octet rule.
The octet rule means that
elements tend to combine so
that each atom has 8 electrons
in its outermost shell.
This results in the formation of
structures such as crystals or molecules.
There are 2 main types of chemical
bonds, ionic bonds and covalent bonds.
Ionic bonds are bonds where the
transfer of electrons takes place.
Let’s see how this type of bond works.
Here we have a sodium atom, which has
an atomic number of 11, meaning it has
11 protons in its nucleus and 11 electrons
in its shells or energy levels.
Shell 1 has 2 electrons, shell 2 has 8
electrons and shell 3 has 1 electron.
And here we have a chlorine
atom, which has an
atomic number of 17, so 17
protons and 17 electrons.
It has 2 electrons in shell 1,
8 in shell 2 and 7 in shell 3.
We know that atoms want to have 8
electrons in their outer shell,
so Sodium can give up one electron, and now
it has 8 electrons in its outer shell,
and chlorine can take that
electron from sodium and
that will give it 8 electrons
in its outer shell.
Since the sodium atom gave up an
electron it has 11 protons, which
are positively charged, and 10 electrons
which are negatively charged.
This results in the formation of a
sodium ion with a positive charge.
An ion is an atom or molecule
with a net electrical
charge due to the loss
or gain of an electron.
Since the chlorine atom gained an
electron, and now has 17 protons
and 18 electrons, it is a chloride
ion with a negative charge.
The positively charged sodium
ion is now attracted to the
negatively charged chloride ion,
and NaCl or table salt is formed.
This is an ionic bond.
So, ionic bonding is when
an electron transfer takes
place and generates 2
oppositely charged ions.
Now for covalent bonds.
Covalent bonds are chemical
bonds that are formed
by the sharing of one or
more pairs of electrons
by the outer energy levels
or shells of two atoms.
The 4 major elements of the body,
carbon, oxygen, hydrogen and
nitrogen almost always form covalent
bonds by sharing electrons.
So, for instance, 2 hydrogen atoms can
bond by sharing a pair of electrons.
Hydrogen is one of the exceptions
to the octet rule of having 8
electrons in the outer shell,
because it only has one shell.
Let’s look at carbon dioxide or
co2, which forms a covalent bond.
Oxygen has an atomic mass of 8,
so 8 protons, and 8 electrons,
2 electrons in its inner shell and
6 in its outer shell, so, oxygen
atoms want 2 more electrons
for their outer shell.
Carbon has an atomic mass of
6, 6 protons and 6 electrons,
2 in the inner shell and
4 in the outer shell, so
it wants 4 more electrons
for its outer shell.
These fellows can make each other
happy by sharing what they have.
Oxygen atom number 1 can share 2 of
its electrons with the carbon atom,
and in return the carbon
atom can share 2 of
its own electrons with
oxygen atom number one,
making oxygen atom number one happy.
Then oxygen atom number 2 can come
in and like oxygen atom number
one it can share two of its
electrons with the carbon atom,
and again in return the carbon atom
has 2 more of its own electrons
that it can share with
oxygen atom number 2.
So now all 3 atoms are happy.
By sharing 2 pairs of electrons in
this situation a double bond has
been formed, and double bonds are
important in chemical reactions.
And that, be the basics on
attractions between atoms.
