Ring test: To the nitrate salt, add freshly prepared $FeSO _{4}$ solution and then cone $H _{2} SO _{4}$ carefully by the sides of test-tube. A dark brown ring of ferrous nitrososulphate is formed.
$NaNO _{3}+ H _{2} SO _{4} \longrightarrow NaHSO _{4}+ HNO _{3}$ $2 HNO _{3}+6 FeSO _{4}+3 H _{2} SO \longrightarrow 3 Fe _{2}\left( SO _{4}\right)_{3}+2 N O+4 H_{O}$ $FeSO _{4}+ NO \longrightarrow \underset{\text{ferrous nitrososulphate}}{[ Fe \cdot NO ] SO _{4}}$
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.