The cross section below shows sedimentary rock layers containing fossils.
Assuming that these rock layers have not been overturned, which fossil is in the layer that was formed
most recently?

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.