How is a pure substance different from a mixture? A. Pure substances are separated by physical means B. Mixtures cannot be separated by physical means C. A pure substance is heterogeneous D. Mixtures are made up of more than one component.

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?

16. in a reaction that has reached equilibrium, a. the forward and reverse reactions are occurring at the same rate. b. the reactants and products are in equal concentrations. c. the forward reaction has gone further than the reverse reaction. d. there are equal numbers of atoms on both sides of the equation. e. a, b, and d are correct.

Choose an equation that represents an enzyme-catalyzed reaction. (a) enzyme + substrate → enzyme-substrate complex (b) enzyme + substrate ←−→ enzyme + products (c) enzyme + substrate ←−→ enzyme-substrate complex → enzyme + products (d) enzyme + substrate ←−→ enzyme-substrate complex → enzyme-substrate complex + products