THE ATOM
The smallest particle of any material.
“Protons, Electrons & Neutrons
Oh My”

The atom is made up of
three subatomic
particles
• The Proton
• The Electron
• The Neutron
Each particle has a specific
charge and location with
in an atom.
The Always Positive Proton
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Protons are
positively charged
subatomic
particles.
They are located in
the nucleus of an
atom.
The symbol for the
proton p+.
+
The Neutron

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Neutrons are neutral
subatomic particles,
that means they have
no charge.
They are also located in
the Nucleus.
The Symbol for the
Neutron is “n”.
The Always Negative Electron

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Electrons are
negatively charged
subatomic
particles.
Their
symbol
is
“e
”.
Their location
orbiting around the
nucleus.
-
ISOTOPES
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Some atoms have more neutrons
then they have protons. These atoms
are called Isotopes.
They do not effect the way an atom
reacts with other atoms.
The Next Level
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Electrons do not all
stay inside one
tight space like the
Protons or
Neutrons.
They orbit in 3D
clouds called shells
Filling the Gaps

Electrons are
distributed in shells
of increasing energy
levels, where the
lowest energy shells
are filled first.
The levels
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Each shell can be represented by a
single ring or orbital. This orbital is
the total number of electrons
possible for that energy level.
First ring holds 2eSecond ring holds 8eThird ring holds 18eFourth ring holds 32e-
The Shells Broken Down
When we break
each electron orbital
down into its shells
we see that really
only 2 e- can fit into
each shell.
Once an orbital has
the maximum
number of electrons
it can hold, you fill
the next level.

Periodic Table

You can use the
periodic table to
figure out the
number of
protons and
electrons an
atom has.
Each Element

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An element is matter made up of
only one type atom.
Each element has a specific number
of electrons, protons and neutrons.
Atomic Number

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The atomic
Number will always
be at the top.
It represents the
number of protons
that element has.
Atomic Mass

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The quantity of
matter in the
atom.
Remember that
most of an atom is
made up of
protons and
Nuetrons.
Balance

We will need to know how many electrons
are in each atom for the element.
Elements like to balanced. That means there
are the same number of electrons as there
are protons.
Nuetrons

To find the number of Nuetrons
simply round the atomic mass to the
nearest whole number and then
subtract from the atomic number.
Periodic Law
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Modern tables are arranged by the
atomic number (the number of
protons).
When arranged this way elements
with similar properties line up or are
close to each other.
This is called Periodic Law.
Periods
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Each row of the
periodic table is a
period.
Elements in the
same period have
the same number
of atomic orbitals.
Groups
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Each column is
called a Group.
Each element in a
group has the
same number of
electrons in the
outer orbital.
Families

Certain elements may
have similar physical
properties and act the
same even if they have
different orbital shells
and different numbers
of protons, these are
families.
The Stable Atom
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Atoms like to be stable.
Only when an atom’s outer orbital is
filled is it stable.
Atoms will combine or react with
each other to become stable.
“Molecules”
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When two different atoms combine
they form a molecule.
For example if we combine two
Hydrogen Atoms with one Oxygen
Atom what molecule do we get?
Compounds
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Put those molecules together and
you have a compound.
A compound is any substance that is
made up of two or more atoms
bonded together.
Types of Bonds

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A chemical bond is when two atoms
join their electrons.
There are four main types of bonds.
Ionic Bonds
Metallic Bonds
Covalent Bonds
Hydrogen Bonds
Ionic Bonds

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Some atoms are able to fill their
outer orbital by giving up or gaining
an electron.
In other words STEALING!
Ionic bonds

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When an atom gives up an electron the
atom has more protons then electrons and
becomes positively charged.
When an atom gains an electron the atom
has more electrons than protons and
becomes negatively charged.
Ions
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An atom that loses an electron has a
positive charge, we call these
CATIONS.
An atom that gains an electron has a
negative charge, we call these
ANIONS.
Ionic Compounds
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Positively charged atoms are
attracted to negatively charged
atoms.
When they come together they form
an ionic compound.
Metallic Bonds
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When metal atoms bond they each
kick out an electron.
These electrons can float freely
around each atom.
Since the atoms are now positively
charged they are attracted to the sea
of electrons and are bonded.
Covalent Bonding


Some times atoms can share electrons to
fill their outer orbital.
Sharing = covalent bond
Hydrogen Bonds

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When hydrogens combine with other
atoms the Hydrogens stay slightly
positive and the other atom stays
slightly negative.
This is called polarity.
Hydrogen Bonds

When two polar molecules come
together the weakly positive
hydrogen will be attracted to the
weakly negative other atom.

This is called a Hydrogen Bond.

Water is the best example.