Here's why:

* Atomic number: Fluorine has an atomic number of 9, meaning it has 9 protons and 9 electrons.

* Electron configuration: The electron configuration of fluorine is 1s²2s²2p⁵.

* Energy levels: The first energy level (n=1) can hold a maximum of 2 electrons, which are in the 1s orbital. The second energy level (n=2) can hold a maximum of 8 electrons, distributed in the 2s and 2p orbitals.

* Fluorine's second level: The 2s orbital holds 2 electrons, and the 2p orbital holds 5 electrons, making a total of 7 electrons in the second energy level.

Therefore, the second energy level of fluorine has 2 electrons in the 2s orbital and 5 electrons in the 2p orbital.