Which of these statements is not true about chemical reaction rates? a) temperature can change a reaction rate b) the amount of reactants can increase the reaction rate c) temperature can decrease the reactions rate d) temperature does not affect the reaction rate

Temperature can change a reaction rate because adding or taking away heat means energy is being added or taken away. When energy is added, the particles speed up, so there is a greater chance of the reactants colliding to form the products, which increases the reaction rate. When energy is taken away, the particles more slower, so they don't collide as easily, which slows down the reaction rate.

Therefore, the answer is D.