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Modern Periodic law:- The Modern Periodic law states that the properties of elements are periodic functions of their atomic number.
# In Modern Periodic Table elements are arranged in increasing order of their atomic number.
# There are seven periods (horizontal rows) and 18 groups(vertical columns) in the Modern Periodic Table.
#The 1st group elements are called alkali metals. Li,Na,K etc.
#the 2nd group elements are called Alkaline earth metals.ex:- Be, Ca, Mg etc.
#17th group elements are called Halogens.Ex:- F,Cl,Br etc.
#18th Group elements are called inert gases. Ex:-He, Ne, Ar
