Write the sub-shell electronic configuration P – group 17

The electrons in an atom can be arranged in shells (or energy levels).

The number of the period of the periodic table tells us which shell (energy level) is being filled.

Period 1: K shell (1st energy level) filling

Period 2: L shell (2nd energy level) filling

Period 3: M shell (3rd energy level) filling

Lower energy levels are filled before higher energy levels.

Each shell (energy level)

sodium (na), for example, has one electron in its valence shell. this is an unstable state because that valence shell needs eight electrons to be full. in order to fill its valence shell, find a way to add seven electrons to its valence shell

increased stability in the completion of fluorine's outer shell.