Modern Periodic Table

Modern periodic table : Scientists kept on the research of finding the solution of the drawbacks found

on Mendeleev’s periodic table. In 1913 Henery Moseley found that the physical and chemical properties of elements are periodic function of their atomic number and not like as stated by Mendeleev.On the basis of this principle he published new periodic table which is known as Modern Periodic Table.
Modern periodic rule: the physical and chemical properties of elements are periodic function of their atomic numbers.
Features of modern periodic table:

• There are seven periods on modern periodic table and the feature is like below

 

Period	First	Second	Third	Fourth	Fifth	Sixth	seventh
No of elements	2	8	8	18	18	32	26
Feature of period	Very short	Short	Short	Long	Long	Very long	Incomplete long

 

•   There are 9 groups along with group VIII and group 0

• The lanthanide series includes elements 58 to 71, which fill their 4f sublevel progressively. The actinides are elements 89 to 103 and fill their 5f sublevel progressively. 
• The elements with valency 0 are placed on last group of periodic table(18), which are called elements of zero group
• 10 elements from group IIIB to group IIB are placed between reactive metals and non metals. They are called Transition Elements.