Can someone double check my work? I'm really not sure about the last one, but I do need all of them checked. I got:
a) exo
b) endo
c) endo
d) endo

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

What is the average rate of the reaction between 10 and 20 s?

Scientists discovered fossils in several layers of the earth you see here. they found fossils of algae, snails, and clams in layer d. given that information, where do you think they found fossil evidence of simple land plants and amphibians?