Excess of ammonia $\left( NH _{3}\right)$ when reacts with sodium hypochlorite solution (NaOCl) in presence of glue or gelatin gives hydrazine $\left( NH _{2} \cdot NH _{2}\right)$ This process is known as Raschig process
$2 NH _{3}+ NaOCl \to N _{2} H _{4}+ NaCl + H _{2} O$
Addition of gelatin or glue suppress the side reaction by complexing with the metal ions and yield of hydrazine is increased.
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.