Inside a star there are two primitive force competing with each other. 1st is the gravitational force which attracts the star's mass towards its core and shrinking the star, due to which the temprature and pressure increases and nuclear fusion stars which releases energy applying a outward radiation pressure(IInd force) balancing the gravitation force and saves the star from shrinking and exploding. any star do not have enough pressure and temperature to convert the nucleus of iron to further elements (by nuclear fusion). so the nuclear fusion inside the star stops. so the gravitasional force overcomes the radiation pressure and the star shrinks and explodes known as supernova explosion and that explosion has enough Temp. and Pressure to form all the further nuclei from iron. 90% of the star's masses gets distributed in space(Starting of a new universe) and the remaning 10% mass forms a neutron star (having no charge).

Inside a star there are two primitive force competing with each other. 1st is the gravitational force which attracts the star's mass towards its core and shrinking the star, due to which the temperature and pressure increases and nuclear fusion stars which releases energy applying a outward radiation pressure  (IInd force) balancing the gravitation force and saves the star from shrinking and exploding. No star has enough pressure and temperature to convert the nucleus of iron into further elements (by nuclear fusion). So the nuclear fusion inside the star stops. The gravitational force overcomes the radiation pressure and the star shrinks and explodes known as supernova explosion and that explosion has enough Temperature and Pressure to form all the further nuclei from iron. 90% of the star's masses gets distributed in space  (Starting of a new universe) and the remaining 10% mass forms a neutron star (having no charge).