Determine the number of protons, neutrons, and electrons in the following isotopes that are used in medical diagnoses:
a. atomic number 9, mass number 18, charge of 1-
b. atomic number 43, mass number 99, charge of 7+
C. atomic number 53, atomic mass number 131, charge of 1-
d. atomic number 81, atomic mass number 201, charge of 1+
e. Name the elements in parts (a), (b), (c), and (d).