Final answer:
The entity with 15 protons, 14 neutrons, and 16 electrons is both an isotope and an ion, specifically a phosphorus anion and an isotope distinct from the most common form of phosphorus.
Step-by-step explanation:
The entity with 15 protons, 14 neutrons, and 16 electrons is both an isotope and an ion. An atom becomes an isotope due to the presence of a different number of neutrons compared to another atom of the same element. In this case, the atom has 15 protons, which identifies it as phosphorus (P), and the number of neutrons (14) makes it a specific isotope of phosphorus different from the most common one which has 16 neutrons. This entity is also an ion because the number of electrons is not equal to the number of protons (16 electrons vs. 15 protons), indicating a net negative charge (1-). Hence, it is a phosphorus anion with one extra electron.