As we know that convection in the earth mantle such as magma drive plate tectonics. Heat generated from the radioactive decay of elements deep in the interior of the Earth creates magma in the aesthenosphere. The aesthenosphere is a part of the mantle where the middle sphere of the Earth that extends to 2900 km.
Convection currents move tectonic plates when the rising mantle creates heat inside. The radioactive decay of several substances is responsible for the creation of the convection currents.
