Question

write the electron configuration for a neutral atom of fluorine.

Explanation:

Step1: Determine atomic number

Fluorine has an atomic number of 9, so a neutral atom has 9 electrons.

Step2: Fill orbitals

Electrons fill orbitals in the order 1s, 2s, 2p. The 1s orbital can hold 2 electrons, the 2s orbital can hold 2 electrons, and the remaining 5 electrons go into the 2p orbital.
The electron - configuration is $1s^{2}2s^{2}2p^{5}$.

Answer:

$1s^{2}2s^{2}2p^{5}$