how many valence electrons are found in an atom of fluorine?\n1\n5\n7\n9

Answer:

C. 7

Explanation:

Step1: Recall fluorine's atomic number

Fluorine has atomic number 9.

Step2: Write electron - configuration

The electron - configuration of fluorine is 1s²2s²2p⁵.

Step3: Determine valence electrons

Valence electrons are in the outermost shell. For fluorine, the outermost shell is the second shell (n = 2) and it has 2 + 5=7 electrons.