How does convection cause tectonic plates to move? A Convection keeps the plates thin enough to move. B Convection makes the plates solid enough to move. C The rising heat of convection currents moves the almost-liquid rocks. D The pressure of convection bends rocks until they break completely.

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.