Periodic table

In the modern periodic table 106 elements are present. In this 90 are natural elements and remaining are artificial. The elements in the periodic table are placed in a particular table by different scientists.
Newlands - Triad Theory
Debonair - Octant theory
Mendeleev - Atomic weights
Mosley - Atomic number

Periodic table divided into groups and periods. The vertical rows are called groups and horizontal rows are called periods. There are 7 periods and 18 groups in modern periodic table.
1^st Period contains 2 elements - Very short period 
2^nd  and  3^rd  period contains 8 elements - Short period
2^nd  period - Bridge Elements 3^rd  period  - Typical Elements
4^th  and  5^th  period contains 18 elements - Long period
6 th period contains 32 elements (lanthanides) - Very Long Period
7 th period - Incomplete Period (actinides)

In periodic table 18 groups are present. Periodic table divided into 4 blocks.
s block - s orbital contains 2 electrons hence 2 groups.
p block - p orbital contains 6 electrons hence 6 groups.
d block - d orbital contains 10 electrons hence 10 groups.
total 18 groups

s block contains 2 groups
1 st group Alkali Metals - H, Li, Na, K, Rb, Cs,  Fr  - (radio active element)
2 nd group elements are Alkali Earth Metals - Be, Mg, Ca, Sn, Br, Ra -  (radio active element)

p block contains 6 groups
2 group
3  group (boron family),
4  group (carbon family) 
5 group (nitrogen family)
6  group (oxygen family)
7 group  (halogens) 
8 group (noble gases)

d block elements are called Transitional Elements. They contains some special properties.
f block elements are called Radio Active Elements. All these elements are Metals.

Most reactive non-metal - F (Florine)
Most reactive Metal Cs (Cesium)

d - block elements
d block elements shows some spacial properties they are color, magnetic, catalytic, alloys.
Magnetic properties are 
Para - weekly attracted towards magnetic field
Ferro - strongly attracted towards magnetic field
Dia - ripple in magnetic field
d block elements are para magnetic in nature. d block elements shows all these properties due to (n-1)d un paired electrons in the d orbital.

f - block elements
f block elements contains 4f and 5f series.
4f - actinoids (from Cesium to Lutetium)
5f - lanthanides  (thorium to  Lawrencium)
Actinides are start after actinium
Lanthanides they start after lanthanum
f block elements kept bellow the periodic table.