The speed of the molecules or atoms in a substance: a) Is equal to the substance's potential energy
b) Varies depending on the type of substance, such as metal, non-metal, ionic compound, or covalent compound
c) Is directly proportional to it's temperature
d) Is always constant

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.