Final answer:
1) Exothermic
ATP hydrolysis is a spontaneous, exothermic reaction with a negative delta G and an increase in entropy, which makes it exergonic.
Step-by-step explanation:
The reaction of ATP hydrolysis is spontaneous because it has a negative delta G (delta G), indicating that it releases energy and proceeds without external energy input.
Additionally, a positive change in entropy signifies an increase in disorder, which, according to the second law of thermodynamics, is favored in spontaneous processes. When considering whether the reaction is endothermic or exothermic, we refer to whether energy is absorbed or released, respectively.
Given that the reaction releases energy (as indicated by a negative delta G), it is an exergonic reaction, meaning it is also exothermic. Thus, the overall characteristics of ATP hydrolysis in terms of thermodynamics are that it is exothermic and accompanied by an increase in entropy, rendering it spontaneous under standard conditions.