Question

I’m having hard time to understand can someone answer it and explain it

Answer 1

Number #2 is joule

In the SI system the unit of heat is the joule. The calorie was defined so that the heat capacity of water was equal to one.The heat capacity of a substance is the amount of heat required to raise the temperature of a defined amount of pure substances by one degree.

Number #3 is Endothermic

Why? I can't explain. I Just left class where they were just explaining that.