Atomic structure.
In this video we are
going to go over atomic
structure in a very
simplistic and basic way.
Atoms are the basic unit
of chemical elements.
They contain subatomic
particles in their nucleus and
in the electron cloud that
surrounds the nucleus.
These subatomic particles
include protons and
neutrons, which are
located in the nucleus,
and electrons, which are located in the
cloud, or field that surrounds the nucleus.
Protons have a positive
electrical charge, neutrons
are uncharged, and electrons
have a negative charge.
The number of protons and
electrons are equal,
so atoms are electrically
neutral particles.
If we look at a model of the
element carbon, which has
6 protons, 6 electrons, and
in most cases 6 neutrons,
we can see the electrons in simple rings
or shells surrounding the nucleus.
Each shell represents a
different energy level,
and it can only hold a certain
maximum number of electrons.
In chemical reactions between
atoms, only the electrons in the
outermost shell participate in
the resulting chemical bond.
In atoms with only one
energy level or shell,
2 electrons are required for stability.
If we look at helium, which has
only 1 shell or energy level,
we see that it is full, because
it contains 2 electrons.
So helium is stable,
and there is no naturally occurring
compound containing helium.
Hydrogen, which also has only
one ring or shell, possesses
only one electron in its shell, so
it is chemically reactive.
In atoms with more than one
energy level or shell, 8
electrons are required in its
outermost shell for stability.
So, neon, which has 8 electrons in
its outermost shell, is stable,
and oxygen, which has only 6 electrons in
its outmost shell, is chemically reactive.
Atoms that do have fewer than 8
electrons in their outermost shells,
will try to share, gain, or lose
electrons in order to become stable.
This is called the octet rule,
but there are some exceptions,
such as we saw with hydrogen and helium
which only have one energy level or shell.
And that, be the basics
on atomic structure.
