Define mass defect.
The table below shows the mass defects of three nuclei.
The nuclear fusion process in a particular star is described by
where 
is a particle that has no mass defect.
State the name of particle .
Show that the energy released when one nucleus of 
is formed in this fusion reaction is 
.
The star in (b) has a radius of 
and a luminosity of 
. All the energy released from the formation of is radiated away from the star. All the energy that is radiated from the star has been released in the formation of . Determine:
the mass of produced per unit time by the fusion process
the surface temperature of the star.
.
.
