Answer
a. exothermic
b. exothermic
c. endothermic
d. endothermic
e. exothermic
f. exothermic
Work Step by Step
a. energy is released as heat in combustion
b. the surroundings of water absorb its heat when water freezes, so heat is leaving the water and it is exothermic
c. the ice has to absorb heat energy to melt so it is endothermic
d. raising the temperature of the water means the water has to absorb heat so it's endothermic
e. vapor has more energy than liquid and to become a liquid it must release that energy. This makes the process exothermic.
f. Another combustion reaction that releases heat so it is exothermic.
