* Valence electrons are the electrons in the outermost energy level of an atom, which are involved in chemical bonding.

* Electron configuration describes the arrangement of electrons in an atom's energy levels.

* Ne 3s² 3p⁵ tells us:

* Ne represents the electron configuration of Neon, which is a noble gas with a full outer shell (2s² 2p⁶).

* 3s² means there are 2 electrons in the 3s orbital.

* 3p⁵ means there are 5 electrons in the 3p orbital.

Since the 3s and 3p orbitals are in the outermost energy level, the total number of valence electrons is 2 + 5 = 7.