Question

why egg is going in solid after boiling instead in vapour state? while water and other substances going in vapour state on boiling?​

Answer 1

The heat coming from your stove denatures the protein by disrupting some of its bonds that held the molecule into shape. In the case of hard-boiled eggs, the proteins clump together and solidify, causing the egg white and yolk to harden. ... On heating, the molecules unfold and start flopping around.

Answer 2

its this protien that causes egg to became hard when boiling . As when the temprature increases , protien  gains  enough energy to form new, stronger bonds  with other protien molecules . when u boil an egg , the heat first  braks  the protien and then allows the protien to link with other protiens