What is a mass defect? A. The amount of mass missing from a nucleus when compared with the sum of its parts
B. The amount of mass lost as subatomic particles in a nuclear reaction
C. The error in atomic mass measurement due to electron contributions
D. Too much mass gained in a nucleus as a result of nuclear fusion ​

Answerit curves up and levels out.explanationwe assume that the container contains absolutely no ammonia to begin with as it states that "nitrogen gas and hydrogen gas" react to "produce ammonia."at dynamic equilibrium, the product and reactant concentrations are equal.this means that, starting from a concentration of zero, [nh₃] must curve "up" from zero and then level out to a constant concentration.