24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.79 have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

Which statement is actually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.