Chapter 2, Problem

Determine the number of protons, neutrons, and electrons in the following isotopes that are used in medical diagnoses:

1. atomic number 9, mass number 18, charge of 1−
2. atomic number 43, mass number 99, charge of 7+
3. atomic number 53, atomic mass number 131, charge of 1−
4. atomic number 81, atomic mass number 201, charge of 1+
5. Name the elements in parts (a), (b), (c), and (d).