According to the law of conservation of energy, which changes would increase the total energy of a system?
O A. An addition of 400 J of thermal energy and a loss of 550 J of
kinetic energy
B. An addition of 200 J of thermal energy and a loss of 550 J of
thermal energy
C. An addition of 300 J of GPE and a loss of 450 J of thermal energy
D. An addition of 500 J of kinetic energy and a loss of 450 J of
thermal energy

the millers tale is the answer.

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.