1)During an endothermic reaction, total energy

Question

A. decreases.
B. increases.
C. stays the same.
D. cannot be determined.

2)The enthalpy of formation of an element is
A. negative.
B. positive.
C. zero.
D. negative or positive, depending on which element.

i think number 1 is A
for number 2 i marked C on my test, but i have mixed feelings that it could be D can you please help
Thank you

Answer 1

2 is C for sure.
#1 is not that easy I don't think. The question asks about total energy but provides only the fact it is endothermic. Endothermic tells you that the reaction absorbs heat from the surroundings in order to occur. It doesn't say anything about the total energy; i.e., nothing about delta S for you to calculate delta G.

Answer 2

I believe that the answer to 1 is C because, according to the first law of thermodynamics, energy can be converted from one form to another but is neither created nor destroyed. So, the total energy of the universe would remain the same even if the system's energy decreases and the surrounding's energy increases. 2 is C.