The modern periodic table the history

1. The Modern Periodic Table
Chapter 5
The
History

2. Chapter 5 – The Periodic Law
By 1860, over ____ elements had been
discovered.
Scientists were using different _______
________ for the elements.
They got together and decided on the
________ ________ _________.
60
atomic
masses
average atomic masses

3. Dmitri Mendeleev and Periodicity
Noticed that when elements were arranged in
order of ___________ ________ _______,
certain similarities in ___________ occurred
at regular intervals.
Such a repeating pattern is referred to as
___________.
He created the first periodic table based on
________ __________.
atomicincreasing mass
properties
periodicity
atomic masses

4. The first published periodic table by
Mendeleev

5. Henry Mosely and the Periodic Law
In 1911, he was working with ____________.
He noticed a pattern when elements were
arranged in increasing nuclear _________
(# of ________).
This work lead to the modern definition of
________ _________.
The periodic table is now arranged according
to ________ _________.
Rutherford
charge
protons
atomic number
atomic number

6. Periods of the Periodic Table
________ across the periodic table
There are ____ periods.
Rows
7

7. Groups of the periodic table
also called ___________
the _________ (up & down) of the periodic
table.
elements of the same group have similar
_________.
There are ___ groups
Groups 1, 2, 13, 14, 15, 16, 17, 18 also
called: ______________________________
families
columns
properties
18
1A, 2A, 3A, 4A, 5A, 6A, 7A, 8A