In which of the following orbitals is the fifth valance electron
in a fluorine molecule situated?

p-orbital

The atomic number of fluorine is 9. So, the electronic configuration of fluorine is  .

Since valence electrons refer to the electrons in the outermost shell; the fifth valence electron is in the p-orbital  ().

So, the fifth valence electron of fluorine occupies the p-orbital.

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p-orbital

Explanation:

Fluorine has an atomic number of 9, hence an electronic configuration of 1s2, 2s2 2p5.

Since, valence electrons refers to the electrons in the outermost shell; counting from the starting orbital and energy level where the 7 valence electrons of fluorine occupy, the fifth valence electron is in the p-orbital of the second energy level (2p5)

Thus, the fifth valence electron of fluorine occupy the p-orbital