When water particles are heated to their boiling point, they begin to change form into a gas.
Not 100% if this answers however:
The radium nucleus turns into radon-222 nucleus, itself radioactive, containing two protons and two neutrons less. The disintegration releases 4.6 million electronvolts of energy. The alpha particle carries the 222/226ths of this available energy and the radon 4/226ths.
N2 is non polar because electronegative of both the atoms are same and N2 also have linear shape