Consider the reaction pictured below in which a molecule of X₂ reacts with a molecule of Y₂ to form two molecules of XY. The reaction is exothermic. Which of the following statements involving the bond enthalpies of X2, Y2, and XY is or are true?

i. 𝐷(X—X),𝐷(Y—Y), and 𝐷(𝑋—𝑌) all have positive values.

ii. 2𝐷(X—Y)<𝐷(X—X)+𝐷(Y—Y).

iii. Δ𝐻=𝐷(X—X)+𝐷(Y—Y)−2𝐷(X—Y).