Answer:
The atomic mass is: 17
Step-by-step explanation:
The atomic mass of a compound is calculated as the sum of protons and neutrons. In this case:
Atomic mass = protons + neutrons = 8 + 9 = 17.
Atoms with the same atomic number (Z) but different atomic mass (A) are called isotopes, that is, they differ in the number of neutrons. Example: Hydrogen, Titrio and Deuterium.