What must happen before a chemical reaction can begin? a. The activation energy must be exceeded.
b. The activation energy must be reached.
c. The concentrations of products and reactants must be equal.
d. The concentration of reactant molecules must be reduced.

Im is in a crowd of people at the mall looking for his girlfriend tammy, who was supposed to meet him for dinner. jim realizes tammy is across the room as he catches a whiff of her overpowering perfume, 'paris #6'. which process explains why jim is able to smell the perfume?

In this assignment, you will analyze an example of speciation by researching the finches of the galapagos islands. then you will answer questions to construct explanations and draw conclusions based on the information you gather. someone plz !

Which to produce involved from a symbiotic relationship of organisms which resulted in eukaryotic organisms contain chloroplast