Answer:
Atomic Number = 9
Mass Number = 19
Step-by-step explanation:
The atomic number is the total amount of protons in an atom's nucleus. Therefore, if a fluorine atom has 9 protons, the atomic number is 9.
The mass number is the total amount of protons and neutrons in an atom's nucleus. Therefore, if a fluorine atom has 9 protons and 10 neutrons, the mass number is 19 (9 + 10 = 19).