ANAMOLOUS behaviour of second period elements
Reasons for Anomalous Periodic Properties
Even though scientists have over the years have seen some trends, each element is unique in its own unique way. The periodic properties of the second period’s elements are especially anomalous.
The following factors lead to variations in periodic properties and, consequently, in chemical behaviour:
i) These atoms are small.
ii) high electronegativity
iii) Large charge/radius ratio.
iv) Absence of p-π/d-π bond , they can form p-π/p-π bond
These are the causes of the second-period elements’ anomalous periodic properties, but there are also several other normal trends in the periodic table.