When atoms of the hypothetical element X are placed together, they rapidly undergo reaction to form the X2 molecule:
a. Would you predict that this reaction is exothermic or endothermic? Explain.
b. Is the bond energy of X2 a positive or a negative quantity? Why?
c. Suppose ΔH for the reaction is -500 kJ/mol. Estimate the bond energy of the X2 molecule.