The answer is C. They lower the activation energy of an elementary step of a reaction
This makes the reaction rate to increase since less energy is required to make a reaction occur.
Answer:
It is expressed as a multiple of one-twelfth the mass of the carbon-12 atom, 1.992646547 × 10−23 gram, which is assigned an atomic mass of 12 units. ... In this scale 1 atomic mass unit (amu) corresponds to 1.660539040 × 10−24 gram.
D) Chlorine, Cl. Hope that helped
Most of our data are based on published information from the Association of American Medical Colleges, the Educational Council for Foreign Medical Graduates, the American Board of Medical Specialties, and the National Resident Matching Program. Data on board-certified physicians were obtained from the Division of Survey and Data Resources of the American Medical Association and are not published elsewhere
i think thats right