In the earths mantle heat is transferred in large convection currents within currents

This question is incomplete. Here is the complete question:

In the Earth's mantle, heat is transferred in large convection currents. Within these currents,

A.cooler and hotter rock rise but do not sink.

B.hotter and cooler rock sink but do not rise.

C.hotter rock rises and cooler rock sinks.

D.cooler rock rises and hotter rock sinks.

The correct answer is option C.hotter rock rises and cooler rock sinks.

Explanation:

Within the mantle of the earth we can find molten rock that burns at very high temperatures, this rock is called magma.

When this magma rises to the surface it begins to cool forming rocks. The densest rocks, which are the coldest, sink, and the least dense rocks that are the hottest rocks, rise.

This process that includes temperature changes in the molten matter that is inside the mantle, is called convection.

Given this information we can say that the correct answer is option C.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

the ratio of the conjugate base to the acid required to attain the desired ph.