The curve of binding energy per nucleon as a function of atomic mass number has a sharp peak for the helium nucleus. This implies that helium

Degenerate electron pressure will not be sufficient to prevent the core collapse of a white dwarf if its mass becomes $n$ times the solar mass. The value of $n$ is:

The equivalent energy of a mass equal to $1 \, a.m.u.$ is

For which mass number range is the binding energy per nucleon maximum?

Draw conclusions from the two main features of the graph of binding energy per nucleon versus the atomic mass number $(A)$.

The figure shows a plot of binding energy per nucleon $E_b$ against the nuclear mass $M$. $A, B, C, D, E, F$ correspond to different nuclei. Consider four reactions:
$(i) \, A + B \to C + \varepsilon$
$(ii) \, C \to A + B + \varepsilon$
$(iii) \, D + E \to F + \varepsilon$
$(iv) \, F \to D + E + \varepsilon$
where $\varepsilon$ is the energy released. In which reactions is $\varepsilon$ positive?