(a)[2]
Describe the energy transfers occurring while the cloud collapses and becomes the protostar.
(b(i))[1]
State in what way the nuclei of isotopes of the same element differ.
(b(ii))[1]
Explain why hydrogen-3 is unable to decay by alpha particle emission.
(b(iii))[2]
Complete the equation for the decay of hydrogen-3 to a helium (He) isotope. $^{3}_{1}\text{H} \rightarrow \; \ldots\, \beta \; + \; \ldots\, \text{He}$
(b(iv))[3]
Explain how the nuclear reaction inside the protostar prevents any further collapse as the protostar turns into a stable star.
(c)[1]
State which stage in a star’s life cycle is responsible for forming the heaviest elements.