7. how do catalysts speed up reactions?
a. they increase the surface area of reactants.

b. they increase the temperature of the reaction.

c. they stir the reactants, causing more particle collisions.

d. they lower the energy barrier of a reaction.

urgent

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?

Energy flows from the producer level to the level. is called

What is an aquifer for science class