Melamine should be the right answer, i hope this helps.
I think the correct answer from the choices listed above is the first option. She concluded that the reaction is an exothermic one because t<span>he reaction released heat. Exothermic is when heat goes out of the system. The opposite is referred to as an endothermic reaction.</span>
well , it's true because they are of sp3d type occur on sets of four
