Answer: Hot material near the core is less dense and rises, and when it cools, it becomes more dense and sinks
Explanation:
The material closer to the core gets heated, making its particles move faster and its density to decrease. Therefore, it rises from the bottom.
As that warm material gets to the surface it gets cooler due to the lack of heat influence from the core. When it becomes cool, its density grows which makes it sink back down.
