The Periodic Table
History of the Periodic Table
Dmitri Mendeleev organized
elements according to their
increasing atomic mass and their
physical properties
Lother Moseley arranged the
periodic table according to the
atomic number
Dmitri Mendeleev’s Table
Reading the Squares
Each square on the periodic table
represents one atom
In each square it tells the following
information about each element
Atomic Number
Atomic Mass
Element Name
Element Symbol
Reading the Periodic Table
Each horizontal row of elements (from
left to right) is called a period
Elements follow a repeating pattern
as you move across the period
Each period moves from metals to
nonmetals
Horizontal row is the
period
Reading the Periodic Table
Each column of elements (top to
bottom) are called a group
Elements in the same group have
similar physical and chemical
properties
Sometimes groups are called
families
Vertical column is the
group
Properties
Determined by the number of
electrons in the outer energy
level of the atom
Same number in the outer shell
will be in same group
oxygen
K Na
lithium potassium
Corrode
sodium
oxygen
Reading the Periodic Table
Elements are classified as metals,
nonmetals and metalloids
The zigzag line on the periodic table
helps you to recognize which
elements are metals, nonmetals and
metalloids
The color of the element symbol tells
whether it is a solid, liquid or gas
Color your table as metals,
metalloids, and non-metals.
Metals
Metals are to the LEFT of the
zigzag line
Most elements are metal
Most metals are solid at
room temperature Exception to the rule: Hg (mercury)
is liquid at room temperature
Metals
Three or fewer electrons in the
outer shell
Good conductor of heat and
electricity
Shiny luster
Malleable
Nonmetals
Nonmetals are to the RIGHT
of the zigzag line
Found as a solid and a gas Exception: (Br) Bromine only liquid
non metal.
Nonmetals
Five or more electrons in the
outer shell
Lack luster
Does not conduct heat or
electricity
Not malleable
Metalloids
Elements that border the
zigzag line
Metalloids have some
properties of metals and
some properties of
nonmetals
Metalloid
Has properties of
both
Found along the
zigzag line
Example:
(Te)Tellurium