Hydrogenation reactions (for example, the process of converting C==C bonds to C--C bonds in food industry) are facilitated by the use of a transition metal catalyst, such as Ni or Pt. The initial step is the adsorption, or binding, of hydrogen gas onto the metal surface. Predict the signs of ∆H, ∆S, and ∆G when hydrogen gas is adsorbed onto the surface of Ni metal.