Answer:
option C = 9 protons, 10 neutrons
Step-by-step explanation:
Fluorine is halogen element. Its atomic number is 9. Which means that fluorine have nine protons and nine electrons. The atomic number of an atoms is its number of protons or number electron. In electrically neutral atom the number of protons and electrons are always equal.
The mass number of an atom is sum of its number of protons and neutrons. The atomic number of fluorine is nine which means it have nine protons so,
number of neutrons = atomic mass - atomic number
number of neutrons = 19 - 9
number of neutrons = 10
The number of neutrons in fluorine atom are ten.