Answer the following questions about the concept of the Q-value of a nuclear reaction.
(i) Define the Q-value of a nuclear reaction.
(ii) Explain how the sign of the Q-value helps in deciding whether a nuclear reaction is exothermic or endothermic.
(iii) A certain nuclear reaction leads to a decrease in the total rest mass of the system by 3.6×10−30kg. Without performing any numerical calculation, state whether the reaction releases energy or absorbs energy. Justify your answer.