The standard Gibbs free energy of formation ΔGf° of Rb(s), H2(g) and Pb(s) are all zero. Similar to enthalpies of formation, the values of the standard Gibbs energies of formation are zero for the elements in their most stable forms at room conditions 298 Kelvin and one atmosphere pressure.
Data that can be measured, deals with numbers and length,height,area,volume etc.
Answer: Chemical Reactions
Explanation:
Chemical reactions often involve changes in energy due to the breaking and formation of bonds.