The Periodic Table of
Elements
Chapter 17.5 and 17.6
Who made it?
• The first periodic table was
constructed by a Russian Chemist,
Dmitri Mendeleev, in 1869
• Mendeleev arranged the elements in
his table according to their atomic
mass.
• This was later changed to atomic
number which is the way it is arranged
today.
The Periodic Table
• Mendeleev arranged the elements in
such a way that the elements with
similar properties were in the same
column.
• The columns are called groups
– Elements found in the same column are said
to be in the same group.
• The rows are called periods
– Elements found in the same row are said to
be in the same period
The Periodic Table
Group
1 2
Group
1st
Period
2nd
Period
3rd
Period
Why is it set up this way
• Mendeleev created his periodic table in this
way because he noticed patterns occurring
with the elements.
• Because he set up his table based on the
patterns he noticed, Mendeleev left blank
spaces in which he was able to predict the
properties of elements that had yet to be
discovered.
• His table was proven useful when these
elements were discovered and had properties
that were a close match to his predictions
Mendeleev's Periodic Table
The Modern Periodic Table
• The Modern Periodic table is not
arranged by atomic mass, but by
atomic number
– Atomic number = number of protons
• Mendeleev did not know about protons in
1872
• There are 18 groups on the periodic
table and 7 periods
The Modern Periodic Table
• The majority of the Elements found on
the periodic table are metals
– Metals are shiny, opaque, and are good
conductors of electricity and heat
– Many of them are malleable, meaning they
can be hammered into shape or bent with
out breaking
– They are also ductile, which means they can
be drawn into wire.
– Most are solid at room temperature except
for Mercury (Hg), Gallium (Ga), Cesium (Cs),
and Francium (Fr).
The Periodic Table
• All of the non metal elements are found
on the right of the Periodic Table,
except for Hydrogen.
– Non metals are very poor conductors of
electricity and heat.
– They are brittle and shatter when
hammered.
The Modern Periodic Table
• The modern Periodic Table has a line
that separates the metals from the nonmetals.
• This line is often referred to as the
staircase.
The Modern Periodic Table
• The modern Periodic Table has a line
that separates the metals from the nonmetals.
• This line is often referred to as the
staircase.
• To the left of the stair case are the
metals (except Hydrogen!)
Metals
NOT HYDROGEN!
The Periodic Table
• The modern Periodic Table has a line
that separates the metals from the nonmetals.
• This line is often referred to as the
staircase.
• To the left of the stair case are the
metals (except Hydrogen!)
• To the right of the stair case are the
non metals.
– Don’t forget Hydrogen!
Metals Non- Metals
The Periodic Table
• The modern Periodic Table has a line
that separates the metals from the nonmetals.
• This line is often referred to as the
staircase.
• To the left of the stair case are the
metals (except Hydrogen!)
• To the right of the stair case are the
non metals.
– Don’t forget Hydrogen!
• Along the stair case are a special
group called metalloids
•Metalloids have some
characteristics of metals and
some characteristics of non
metals
•They are in-between
metals and non metals
The Atom and The Periodic Table
• Aside from metals and non metals the
periodic table is organized in two ways.
• These two ways are in
– Groups/Families
– Periods
Rows on the Table
• Remember, the atomic number = the
number of electrons.
• The first row has Hydrogen with one
electron and Helium with two electrons
both in energy level one.
• Therefore, Helium has the first energy
level full.
• We consider this as being stable.
Rows on the Table
• If you look at the second row, it starts
with lithium and ends with neon.
• Lithium has three electrons and neon
has ten electrons.
• Lithium has two electrons in the first
shell and one in the second.
• Neon has two electrons in the first
shell and eight in the second.
• The first column always starts the
new shell.
• The last column always fills the shell.
Groups
• Groups or families are the
vertical columns on the
periodic table.
• Groups are numbered 1
through 18.
• These elements have the
same number of
electrons in their outer
The group IIa elements; beryllium,
orbits.
magnesium, calcium, strontium, &
– Valence Electrons!
• They also have many
characteristics in
common.
barium. They are called the Alkali
Earth Metals.
Alkali Metals
• The first group of elements on the
periodic table are called The Alkali
Metals
Alkali Metals
Alkali Metals
• The first group of elements on the
periodic table are called The Alkali
Metals
• The Alkali Metals are very reactive
• Many of them like sodium react
violently with water
• As you move down the group they
become more and more reactive
Alkaline Earth Metals
• The second group on the periodic table
are called Alkaline Earth Metals
Alkaline Earth Metals
Alkaline Earth Metals
• The second group on the periodic table
are called Alkaline Earth Metals
• Alkaline Earth Metals react with water
but not as violently as Alkali Metals
• Alkaline Earth Metals also do not melt
or change when placed in fire
Transition Metals
• Group 3 through 12 are known as the
Transition Metals
Transition Metals
Transition Metals
• Group 3 through 12 are known as the
Transition Metals
• Transition metals are the more familiar
metals such as copper, gold, silver,
iron, nickel, and chromium.
• These metals are usually shiny, do not
react well with water, and melt when
heated
Inner Transition Metals
• The inner transition metals belong in
the 6th and the 7th period
Inner Transition Metals
Inner Transition Metals
• The inner transition metals belong in
the 6th and the 7th period
• The Lanthanide Series belongs in the
6th period because of its properties
• the Actinide Series belongs in the 7th
period because of its properties
• Inserting them into the Periodic Table
would make a long periodic table that
wouldn’t fit on a piece of paper!
• Uranium, an actinide, is used in nuclear
power plants
Groups 13-16
• Groups 13-16 have no common names but
contain many elements familiar to us.
• Boron, Carbon, Nitrogen, & Oxygen can all be
found in groups 13 through 16
• Since they don’t have a special name we just
use the first element in the group as the name
– ie. Boron Group
• Each member of the group has the same
number of valence electrons
• Some of these elements are metals, metalloids
or non-metals depending on where they are
found relative to the stair case
Boron
Group
Carbon
Nitrogen
Oxygen
Group
Group
Group
Halogens
• Group 17 are known as the Halogens
Halogens
Halogens
• Group 17 are known as the Halogens
• Halogens in Greek mean “salt forming”
• Many elements in this group form salts
with metals
Chlorine is a
– Ie. Sodium Chloride
Halogen
• Some Halogens such as Bromine and
Iodine are found in Halogen lamps
which glow brighter without burning
out quickly
The Noble Gases
• Group 18 are known as the Noble Gases
Noble Gases
The Noble Gases
• Group 18 are known as the Noble Gases
• The noble gases do not react with any
other elements or themselves
• They are chemically stable or unreactive
• They get their name from the Nobles
who would never interact with the
common folk!