1. Atomic Number: Fluorine's atomic number is 9. This tells us that a neutral fluorine atom has 9 protons.
2. Protons and Electrons: In a neutral atom, the number of protons always equals the number of electrons. So, fluorine also has 9 electrons.
3. Mass Number: Fluorine's most common isotope has a mass number of 19. The mass number is the sum of protons and neutrons.
4. Number of Neutrons:
* Mass number - atomic number = number of neutrons
* 19 - 9 = 10 neutrons
Therefore, a fluorine atom has:
* 9 electrons
* 10 neutrons
