The Periodic Table
Before the Periodic Table
…was a mess!!!
No organization of elements.
Difficult to find information.
Chemistry didn’t make sense.
The Periodic Table
Developed in 1886 and 127
years later still the main
idea.
The periodic table is a system which
helps to classify the elements.
In 1735 there were only 13 known
elements.
In 1815 there were 47.
Today there are over 100 including
several man-made elements.
The periodic table that we use today was
devised by a Russian scientist named Dmitri
Mendeleev in 1886
Symbols for the Elements
Symbols can be in written in different
ways:
The symbol for the element is the first letter
of the element’s name capitalized.
Examples:
Using his model, he was able to predict the
properties of missing elements before their
actual discovery took place.
The first letter of the element’s name
Hydrogen
Oxygen
H
O
The first letter of the element capitalized
capitalized and the second letter of the
element’s name in lower case:
and another letter of the element’s name
in lower case:
Example:
Example:
Calcium
Ca
Chlorine
Barium
Ba
Magnesium
Cl
Mg
There are 8 elements that have symbols that don’t follow any
of the 3 rules. The symbols are based on their Latin names!
Lead, Iron, Silver, Gold, Copper, Mercury, Potassium and Tin
English Name
Lead
Latin Name
Plumbum
Symbol
Pb
Silver
Gold
Copper
Mercury
Iron
Potassium
Tin
Argentum
Aurum
Cuprum
Hydrargyrum
Ferum
Kalium
Stannum
Ag
Au
Cu
Hg
Fe
K
Sn
Organizing the Elements
All elements in the periodic table can be
classified into three different categories:
Organizing the
Elements
The Staircase Line
Metals
Most periodic tables will contain a staircase
line which allows you to identify the elements
as either metals, metalloids, or non-metals.
Non-metals
Metalloids
There are certain properties about an element
that places them into their proper category
Metals
Most elements are metals
88 elements to the left of the staircase line are
metals or metal-like elements
Physical Properties of
Metals
Luster
Good conductors of heat and electricity
High density
High melting point
Ductile
Malleable
Most are solid at room temperature
Chemical Properties of
Metals
Easily lose their electrons
Corrode easily – react with oxygen
Physical Properties of
Non-metals
Dull appearance
Poor conductors of heat and electricity
Brittle
Non Ductile
Not malleable
Low density
Low melting point
Metalloids
These elements zigzag on both sides of the
staircase.
Have properties of both metals and non-metals
Non-metals
Non-metals are found to the right of the
staircase line.
Their characteristics are opposite of metals.
Chemical Properties of
Non-Metals
Have a tendency to gain electrons
Since metals tend to lose electrons and non-metals gain
electrons, metals and non-metals like to form
compounds with each other.
Physical Properties of
Metalloids
Solids
Can be shiny or dull
Ductile
Malleable
Conduct heat and electricity better than
non-metals but not as well as metals.
The horizontal rows in the periodic table are
called periods. We number them 1 to 7.
The vertical columns are called groups. We
number them 1 to 18. Some also have special
names.