11 13 15 17 16 18 20 24 32 1. An atom of oxygen with a mass number of 17 and an atomic number of 8 has a total of neutrons. 2. An atom of oxygen with a mass number of 16 and an atomic number of 8 has a total of neutrons. 3. An atom of aluminum with a mass number of 24 and an atomic number of 13 has a total of neutrons. 4. An atom of argon with a mass number of 38 and an atomic number of 18 has a total of neutrons. 5. An atom of phosphorous with a mass number of 32 and an atomic number of 15 has a total of neutrons.