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1.d. Students know how to use the periodic
table to determine the number of electrons
available for bonding.
Review…
• Valence electrons are the electrons that are
found in the outermost shell of an atom.
• Valence electrons participate in bonds (can move
from one atom to another).
1
2
2
34567
8
Ions
• When an atom loses or gains an electron(s),
that atom will become electrically charged
- an
particle (atom)
+
“Take my electron!
TaT
I’m an Alkali
Metal!”
11P
11N
“Give me your
TaT I’m a
electron!
17P
Halogen!”
18N
-
+
11P
11N
17P
18N
Why do atoms that lose or gain electrons
become
?
• Remember….Protons are positive and electrons
are negative
• In neutral atoms (atoms with no charge) the
protons and electrons are equal to one another
• When electrons are lost or gained – the amount
of electrons become increased or decreased
creating an electric charge
How to determine charges on ions?
• Metals LOSE electrons and will become
positively charged.
• Nonmetals GAIN electrons and will become
negatively charged.
LOSE
METALS
eLeft
GAIN
e-
NONMETALS
Right
Alkali Metals Group 1
• Alkali metals have 1
valence electron.
When their one
electron is given
away they become a
+1 charge (positive
charge by 1).
Alkaline Earth Metals Group 2
• Alkaline Earth
metals have 2
valence
electrons. When
their two
electrons are
given away they
become a +2
charge (positive
charge by 2).
The Boron Family Group 13
• Have 3 valence electrons.
• If these elements lose 3 electrons, they
become a +3 charge.
+3
The Carbon Family Group 14
• Can gain, lose, or share four electrons when
reacting with other elements
• If an element gains 4 electrons will become -4
charge.
• If an element loses 4 electrons will become a +4
charge.
• Carbon is the only nonmetal element in the
group.
The Nitrogen Family Group 15
• Will gain or share 3 electrons.
• Nitrogen and Phosphorus are the 2 nonmetals
in this group.
• Arsenic and Antimony are semimetals and
Bismuth is a metal.
• All elements in this group, except Bismuth, will
gain 3 electrons and become a -3 charge.
• Bismuth loses electrons.
The Oxygen Family Group 16
• Will gain or share 2 electrons when reacting
with other elements.
• When these elements gain 2 electrons, they
become a -2 charge.
The Halogens and Ions
• The Halogens are nonmetals and they gain
electrons.
• They have 7 valence electrons and need to gain 1.
• When they gain 1 electron, they become a -1
charge (negative charge by 1).
The Noble Gases and Ions
• They don’t form ions. DUH!!!!
• They have no electrons to lose or gain. They
are stable!
NO BONDS…..FULL
OUTER SHELLS!
LOSE
Either Gain
Nonmetals
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Electrons
Oxidation Number
• Charge of an atom once it has gained or lost
electrons to become stable
Transition Metals
• Remember…the transition elements are
variable.
• They can have multiple oxidation numbers.
• This means they can lose varying amounts of
electrons…creating different charges.
Cations and Anions
• Cation = positively charged ion (metals form
cations
• Anions = negatively charged ion (nonmetals
form anions)
WHEN REMOVING ELECTRONS
THE RESULTING CHARGE IS POSITIVE
Neutral
No Charge
1+
WHEN ADDING ELECTRONS
THE RESULTING CHARGE IS NEGATIVE
Neutral
No charge
3-
An atom with positive or negative charge
is called an
drum roll
ION
Atoms without charge are called ATOMS
Atoms with positive or negative charge
are called IONS
Notice that ONLY the number of e- changes
(Only electrons are added or subtracted)
The number of protons in an
Atom NEVER changes
Ions make up the salt you put on your eggs in
the morning
Ions are required for your brain to function
(ions allow you to see and understand this
presentation)
Ions are an essential ingredient in soap
Ions are required for cellular respiration
Ions make up acids and bases
Ions keep your blood functioning
C6H12O6 + O2 CO2 + H2O