(a)[3]
Describe the arrangement of particles in an atom of helium-4, $^{4}_{2}\mathrm{He}$.
(b(i))[2]
State what occurs during nuclear fusion reactions which produce helium.
(b(ii))[2]
State two regions of the electromagnetic spectrum through which the Sun radiates most of its energy.
(c)[2]
Describe what occurs to a star when most of the fuel in its core has been changed into helium.