Final answer:
Mercury is the gas giant with the shortest period of revolution, while Jupiter has the shortest 'day' among the gas giants.
Step-by-step explanation:
The gas giant with the shortest period of revolution is Mercury.
According to Kepler's laws, Mercury has the shortest orbital period of 88 Earth-days, which results in the highest orbital speed of approximately 48 kilometers per second. This is due to Mercury being the nearest planet to the Sun.
On the other hand, Jupiter has the shortest 'day' of any planet, with a rotation period of 9 hours 56 minutes, determined by the rotation of its atmosphere and core.