When the mantle convects, _1 is transferred through the mantle by physically moving hot rocks. _2. is the result of heat transfer from the core to the base of the lower mantle. Earth's mantle will stop convecting once the _3.has cooled to the point where there is not enough heat transfer to overcome the strength of the rock. There are two major sources of heat flow from Earth's interior. A major source of Earth's heat is _4.the energy released when the unstable atoms decay. The heat that came from radioactivity sources is also known as 5._6._that is, heat lost as Earth continues to cool from the heat generated by the accretion processes that formed it-accounts for the remaining internal heat flow.
