Nitrogen, being smaller in size can effectively from $p \pi-p \pi$ bonds with other atoms of itself and atoms of other elements with small size and high electronegativity such as oxygen and carbon. The other elements do not from $p \pi-p \pi$ bonds because of their relatively lager size.
In other words the $p$ orbital of there elements are larger in size.
P block elements are those in which the last electron enters any of the three p-orbitals of their respective shells. Since a p-subshell has three degenerate p-orbitals each of which can accommodate two electrons, therefore in all there are six groups of p-block elements.
P block elements are shiny and usually a good conductor of electricity and heat as they have a tendency to lose an electron. You will find some amazing properties of elements in a P-block element like gallium. It’s a metal that can melt in the palm of your hand. Silicon is also one of the most important metalloids of the p-block group as it is an important component of glass.