The two things are hypothesis and empirical evidence
Answer is: <span>- delta G.
</span>The change in Gibbs free energy (ΔG), at constant temperature and pressure, is: <span>ΔG=ΔH−TΔS.
</span>ΔH<span> is the change in enthalpy.
</span>ΔS is change in entropy.
T is temperature of the system.
When ΔG is negative, a reaction (<span>occurs without the addition of external energy)</span><span> will be spontaneous (</span>exergonic).
A) sodium fluoride
B) rubidium oxide
C) boron trichloride
D) dihydrogen selenide
E) tetraphosphate hexoxide
F) iodine trichloride