The Periodic
Table
Classification of Elements
Metals, Nonmetals, and
Metalloids
1
2
3
4
5
6
7
• Horizontal rows are called periods
• There are 7 periods
• The 18 vertical columns are called
families or groups.
• Elements are placed in columns by
similar properties.
Group Numbers on the Periodic Table
Group Names
Halogens
Noble Gases
Alkali Metals
Lanthanides
Actinides
Alkaline Earth Metals
Chalcogens
Solid, Liquid, and Gaseous Elements
Periodic Trends
Periodic Trends
• Atomic radius: the distance from the
center of an atom's nucleus to its
outermost electron.
• Since the electron cloud does not have
an exact boundary, the atomic radius is
usually measured by finding the
distance between the centers of two
atoms.
Atomic Radius
• Atomic Radius
– Increases to the LEFT and DOWN
1
2
3
4
5
6
7
Periodic Trends
• Ionic Size: Atoms gain or lose electrons
to gain noble gas configurations, or
pseudonoble gas configurations.
• Metals lose outer electrons forming
cations which are smaller than the
atoms they were made from.
• Nonmetals gain outer electrons forming
anions which are larger than the atoms
they were made from.
Ionic Radius
• Ionic Radius
– Cations (+)
• lose e-
– smaller
–
Anions (–)
•
gain e
• larger
© 2002 Prentice-Hall, Inc.
Periodic Trends
• Ionization energy: the energy required
to remove an electron from a gaseous
atom or ion.
• Removing one electron makes a +1 ion.
• The energy required is called the
first ionization energy.
Ionization Energy
• Ionization Energy
– Increases UP and to the RIGHT
1
2
3
4
5
6
7
Periodic Trends
• Electron Affinity: a measure of an
atom's attraction, or affinity, for an
extra electron.
Periodic Trends
• Atoms that have a greater attraction
for an added electron have a more
negative electron affinity.
• The higher the electron affinity, the
higher the negative value. Nonmetals,
other than the noble gases, have the
greatest electron affinities.
Electron Affinity:
• Electron affinity generally decreases
down a group since the attraction by
the nucleus on the outer level electron
is weakened by the increase in atomic
size.
• Electron affinity generally increases
across a period because the atoms
become smaller and the nuclear
charge increases.
Periodic Trends
• Activity: refers to the tendency of an atom
to react.
• Activity increases toward the lower left
side of the periodic table, for metals.
• Activity increases toward the upper right
corner of the periodic table, except the
noble gases, for nonmetals.
• Fluorine is the most active element. It
reacts with everything except He, Ne, and Ar.
• Noble gases are generally very unreactive.
STOP Presentation
Pass out Periodic Trends worksheet to the
students.
Please read the instructions at the top of
worksheet.
Once students have had time to complete
the worksheet, please continue to show
this presentation for the answers. 
Answers: Trends from
the Periodic Table
#1 What do you expect
the following atoms to do
when bonding with other
atoms?
Bonding Atom
1. Calcium-A-Lose
electrons
2. Fluorine-B-Gain
electrons
3. Neon-C- Neither lose
or gain electrons
4. Argon-C-Neither lose
or gain electrons
5. Oxygen-B-Gain
electrons
Reason
1. Calcium is a metal
2. Fluorine is a
nonmetal
3. Neon is a noble gas
4. Argon is a noble gas
5. Oxygen is a
nonmetal
Bonding Atom
6. Zinc-A-Lose electrons
7. Lithium-A-Lose
electrons
8. Sulfur-B-Gain electrons
9. Helium-C-Neither lose
or gain electrons
10. Sodium-A-Lose
electrons
Reason
6. Zinc is a metal
7. Lithium is a metal
8. Sulfur is a nonmetal
9. Helium is a noble gas
10. Sodium is a metal
#2 Predict the ions
formed by the following
elements
Ion formation
1. Aluminum, Al +3
Reason
1. Aluminum is a metalwhich means it loses
electrons. It is in
Group IIIA (look at the
top of the column in
which Aluminum is
under) It has 3
valence electrons. It
needs to lose three
electrons in order to
have the valence
electrons of the noble
gas Neon (which has 8
valence electrons).
Because it loses 3
electrons it the ion is
positively charged.
Ion Formation
2. Phosphorus, P -3
Reason
2. Phosphorus is a
nonmetal-which mean it
gains electrons. It is in
Group VA. It has 5
valence electrons;
therefore it needs 3
more electrons in order
to have the valence
electrons of the noble
gas Neon (which has 8
valence electrons). It is
-3 because electrons
are negatively charged.
Ion Formation
3. Nitrogen, N -3
Reason
3. Nitrogen is a nonmetalwhich mean it gains
electrons. It is in Group
VA. It has 5 valence
electrons; therefore it
needs 3 more electrons
in order to have the
valence electrons of the
noble gas Neon (which
has 8 valence
electrons). It is -3
because electrons are
negatively charged.
Ion Formation
4. Lead, Pb +4
Reason
4. Lead is a metal-which
means it loses
electrons. It is in Group
IVA. It has 4 valence
electrons. It needs to
lose four electrons in
order to have the
valence electrons of the
noble gas Xeon (which
has 8 valence
electrons). Because it
loses 4 electrons, the
ion is positively
charged.
#3 Predict the number of
valence electrons the
following atoms.
Valence Number
1. Tin, Sn 4
2. Bismuth, Bi 5
Reason
1. Tin is a member of
group IVA. Which
means it has 4
valence electrons
2. Bismuth is a
member of group
VA. Which means it
has 5 valence
electrons.
Valence Number
Reason
3. Silicon, Si 4
4. Strontium, Sr 2
3. Silicon is a member
of IVA. Which means
it has 4 valence
electrons.
4. Strontium is a
member of IIA. Which
means it has 2
valence electrons.
Predict the following electron
configuration
4. Aluminum: 1s22s22p63s23p1
5. Bromine: 1s22s22p63s23p64s23d104p5
Prediction for new element,
atomic number 114
6. Metal: Since it would be in the same column as
Lead-which is a metal. It would lose electrons,
be a good conductor of heat and electricity, have
luster, be ductile and malleable.
7. The number of valence electrons for the new
element 114 is 4 valence electrons, because it
would be in column IV-which has 4 valence
electrons.
8. The ion formation of the new element 114 is +4.
A new element, atomic number
118, was discovered.
9. Predict some properties of this element.
It would be a noble gas, be relatively
unreactive, have 8 valence electrons, form
no ions.