The electrons should just spiral in towards the positive nucleus. Electrons move in fixed orbits, called electron shells, around the nucleus. New evidence The discovery of electrons. Changes to ...

As we move down the column of Group 7 elements, their reactivity decreases. In each, the outer shell is further from the nucleus and the incoming electron is not as easily attracted to it.

Related: Razor-thin crystalline film 'built atom-by-atom' gets electrons moving 7 times faster than in semiconductors To create an exposure time capable of capturing electron movements ...