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.