<span>Heat comes from stove flame to the sauce pan by radiation through infrared energy, heat conducts the metal of the sauce pan; Convection brings cool water to the hot surface at the bottom of the hot sauce pan until all or most of the water is hot enough to boil.</span>
I don't know I guess its the plate tectonics
<span>Exothermic reaction is a chemical reaction that releases energy. This reaction releases heat energy or light .
In an endotermic reaction energy is used.
Enthaply is the heat energy change , delta H.
If the sum of the enthalpies of the reactans is greater than the products the reaction is exothermic. If the products side has a larger enthaply than the process is endothermic. So, if delta H is negative then the process is exothermic. If delta H is positive, than the process is endothermic.
Exothermic are: A+BC -> AB+C
A2+B2 -> 2AB
Endothermic are:AB+C -> AC+B
A2 + C2 -> 2AC
B2+C2 -> 2BC</span>
I would say that this is the first law of thermodynamics.
