5. INTRODUCTION
Shortcomings of Mendeleev's table
His table did not include any of the noble
gases,which were discovered later. These
were added by Sir William Ramsay as
Group 0, without any disturbance to the
basic concept of the periodic table.
A single position could not be assigned to
hydrogen in the periodic table. Hydrogen
could be placed in the alkali metals group
as well as in the halogens group
8. STRUCTURE
Now, we are using Medeleev’s periodic table. It
include 2 part.
Periods
Groups
9. STRUCTURE
There are 7 periods
Include elements which has the same shell
number
Example:
Period 1 1 shell
Period 2 2 shell
Period 3 3 shell
10. STRUCTURE
In the periodic table. Each period has element
number difference and It separate of 2 part.
From 1 to 3 periods: periods small
example: in 2 period, it have 8 elements.
From 4 to 7 periods: periods large
example: in 4 period, it have 18 elements.
11. STRUCTURE
Include element which have the same number
outer electrons
-Groups A consists of the
elements s (IA, IIA) and the
elements p (IIIA to VIIIA)
They are divided into 2 groups: group A & group B
- Groups B consists of the
elements d (the groups B) and the
elements f (last two rows in the
table)
13. PROPERTIES
The rule of periodic table:
Left to right (in the period):
Radius of atoms decrease
Electronegativity of elements increase
The metallic property decrease
The non-metallic property increase
Example:
Na Mg Al Si P S Cl Ar
Non-metallic property
Metallic property
14. The rule of periodic table:
Up to down (in the group):
Radius of atoms increase
Electronegativity of elements decrease
The metallic property increase
The non-metallic property decrease
Example:
Metallicproperty
Non-metallicproperty
PROPERTIES
