Gas giants are known for their
a. rocky exteriors.
c. lack of satellites.
b. ring structures.
d. closeness to the sun.

The correct answer is (b.) ring structures. Gas giants are known for their ring structures. Gas giants are mostly composed of helium and hydrogen. A great example of a gas giant would be the planets Jupiter and Saturn which are considered to be the Solar System's gas giants.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.