One evening last summer, as I strolled along the promenade in Limbe, a small, scenic port town in southwestern Cameroon, I was stopped by a well-dressed young man who greeted me warmly and took me by the hand.
Phosphorus has 3 shells. The outer shell contains 5 electrons. The electronic configuration is :- <br /> 1s2, 2s2, 2p6, 3s2, 3p3.
Rating Newest Oldest. Best Answer: It depends on which isotope. But since phosphorus has an atomic number of 15, signifying 15 protons in the nucleus, and an atomic mass of 30.97, signifying 31 total nucleons, the average number of neutrons must be 31 - 15 = 16. Most atoms have a number of neutrons that is close to the number of protons. Phosphorus with an atomic mass of 31 is the only isotope that occurs in nature, but heavier phosphorus nuclei have been synthesized in labs.