Question

how many electrons does this have (assuming neutral)? 19 9f how many neutrons does this have? 19 9f

Explanation:

Step1: Recall atomic number concept

The number of protons in an atom is equal to its atomic number. For fluorine ($F$), the atomic number is 9 (the sub - script in $_{9}^{19}F$).

Step2: Use neutral atom property

In a neutral atom, the number of electrons is equal to the number of protons. Since the number of protons in fluorine is 9, the number of electrons is also 9.

Answer:

A. 9