Which of the following may suggest a catalyst has been used in a reaction, given the energy diagram for the same reaction without a catalyst?

a. activation energy is 120 kj
b. activation energy is 40 kj
c. activation energy is 60 kj
d. enthalpy is 10 kj
e. enthalpy is 40 kj

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

How are isotopes of the same chemical element alike? how are they different?

Draw the lewis structure for the trisulfur s3 molecule. be sure to include all resonance structures that satisfy the octet rule.