Question

question 2 the change in concentration of reactants over time is always negative. always positive. sometimes positive and sometimes negative.

Explanation:

In a chemical reaction, reactants are consumed over time, so their concentration decreases. The change in concentration (Δ[reactant]) is calculated as final concentration minus initial concentration. Since final concentration of reactants is less than initial, Δ[reactant] is always negative.

Answer:

A. always negative