Periodic Table
Atoms of elements make up the periodic table
It is a ‘map’ of the elements
History of the Periodic Table
• In 1869 a Russian chemist, Dmitri Mendeleev, came up
with the first version of the periodic table.
• He arranged the table by listing elements in order of
increasing atomic mass.
• Mendeleev’s work was not perfect because several elements
seemed to be misplaced.
•
Henry Moseley, a British chemist, corrected the periodic
table in 1913.
• He arranged it by increasing atomic number instead of
atomic mass.
• We call it a periodic table because it shows a repeating, or
periodic, pattern of properties of the elements.
Groups & Periods
• The periodic table is divided into 18 vertical columns
called families and 7 horizontal rows called periods.
• Elements in the same family (columns) have similar
properties.
• Elements in the same period (rows) have properties that
change in a predictable way from one end of the period to
the other.
• The lanthanide elements (row 6) and the actinide
elements (row 7) are separated from the rest of the table
by being placed beneath the table in order to make the
table shorter and easier to read.
• These two rows are called the rare earth elements.
Using the Periodic Table
• The periodic table is divided into 3
major sections:
– The metals
– The nonmetals
– The metalloids
• An atom’s position on the periodic
table indicates basically two things:
– Properties of the element like valence (families)
– How reactive it is (periods)
Touring the Table
• Metals, Nonmetals, & Metalloids
• Periodic Families:
– Family 1
Alkali Metals
– Family 2
Alkaline Earth Metals
– Family 3-12 Transition Metals
– Family 13
Boron Group
– Family 14
Carbon Group
– Family 15
Nitrogen Group
– Family 16
Oxygen Group
– Family 17
Halogens
– Family 18
Noble Gases
The two rows at the bottom are called the rare
earth elements
Element symbols & names
• There is a ‘symbol’ for each element
name and it follows a pattern.
• Always begins with uppercase letter, can
be no more than three letters, and all
other letters are lowercase.
• Element symbols do not always appear
as the abbreviation for the element name.
• Some come from Greek and Latin origins.
Natural elements vs. man made
With two exceptions, #43 & #61,
Elements 1 thru 92 are natural
elements discovered.
Elements 93-118 are synthetic or
man-made elements.