Question

How many electrons does fluorine have? How many electron shells? Name the orbital that is occupied. How many electrons are needed to fill the valence shell?

Short answer

There are nine electrons in fluorine (F) which are distributed in the two electron shells.

1s, 2s, 2p orbitals are occupied. One electron is required to fill the valence shell.

Step-by-step solution

Electrons and electron configuration

The smaller and lighter charged particles that revolve around the nucleus are called electrons. They have a negative charge.

The arrangement of electrons in energy shells that surrounds the nucleus is referred to as electron configuration.

Understanding electron configuration

The electron shells surrounding the nucleus are arranged in a hierarchy, with the shells furthest from the nucleus having the highest energy. Beginning with K, the shells or energy levels are numbered or lettered as follows: K is one, L is two, M is three, etc.

There is just one sub-shell in the first shell, and that sub-shell has only one orbital, the s orbital. The s-orbital can hold two electrons. As a result, the first shell K may accommodate two electrons.

The second energy level has one s orbital and three orbital in the p sub-shell that may house a total of six electrons. As a result, the second L shell can house up to eight electrons in total. The last shell to be filled is referred to as the valence shell.

Electron configuration of fluorine

Fluorine has nine electrons; thus, its electronic configuration is 1s²2s²2p⁵. The electronic configuration of F exhibits that F occupies the first two shells, the K(1) and L(2) shells. The K shell has an s-orbital, which contains two electrons, and the L shell has s- and p-orbitals, so it contains two and five electrons, respectively.

Thus, F has two electron shells in which three orbitals, which are 1s, 2s, and 2p, are occupied by electrons. As F has five electrons in 2p orbital (the valence shell), it needs one more electron to fill the valence shell.