Final answer:
The level of geological activity on a planet is influenced by the decay of radioactive elements, the planet's size, and its age. Larger planets retain heat longer, which drives geological activities, whereas the thickness of a planet's atmosphere and sunlight are not direct factors.
Step-by-step explanation:
The factors that determine a planet's level of geological activity include internal heat sources such as the decay of radioactive elements in its interior, the planet's size, and its age. Larger planets and moons can retain their internal heat for longer periods, much like a large baked potato retains its heat, which is often referred to as the 'baked potato effect'. This retained heat can power geological activities like volcanism and tectonic movements. While the thickness of a planet's atmosphere and the amount of sunlight it receives do affect surface conditions, they are not direct determinants of geological activity. Additionally, geological activity can be induced by tidal heating, as seen with Jupiter's moon Io, which experiences heat from the gravitational pull of Jupiter, and Europa and Saturn's moon Enceladus, where geological activities are believed to be influenced by the planets' gravitational forces.