The subscripts indicate the number of atoms of the element immediately before it.
Answer:
The composition of the objects because not all the planets have been explored
It has the most mass. but the electron cloud takes up the most space.
It’s water vapor, does this help?
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.