2. There are three isotopes of an element: a. The element is: b. The number 58 refers to the 136Ce 58 ABD 138 Ce 58 UM C. The numbers 136, 138, 140, 142refer to the d. How many protons and neutrons are in the first isotope? e. How many protons and neutrons are in the second isotope? f. How many protons and neutrons are in the third isotope? g. How many protons and neutrons are in the fourth isotope? rod 140 Ce 58 fod 142 Ce 58