An unknown substance undergoes a chemical change that gives off heat. Which of the following statements is true?
(will post answer choices in a sec!)

Question

An unknown substance undergoes a chemical change that gives off heat. Which of the following statements is true? 
   (will post answer choices in a sec!)

anonymous · Answer

A.       The types of molecules of the substance before and after the chemical change are the same, and the change was endothermic.
   
B.    The types of molecules of the substance before and after the chemical change are different, and the change was endothermic.
   
C.    The types of molecules of the substance before and after the chemical change are the same, and the change was exothermic.
   
D.    The types of molecules of the substance before and after the chemical change are different, and the change was exothermic.

anonymous · Answer

I think the answer is D (that they are different and that the change was exothermic cuz heat was given off...) Am i right??? Or was the change the same??? OR was it endothermic?? :O

anonymous · Answer

Hi @hba!!! :) THanks again for coming... once again!! :D i really appreciate the help!!! :D SOooo what do u think?? :)

hba · Answer

The types of atoms before and after the change are different

anonymous · Answer

Kk so i got that part right... But is it exothermic (i think it is... cuz it GIVES OFF heat) or is it endothermic??? @hba??