Learn why electron shells are responsible for the properties of elements, and whether they are stable or have violent reactions.
- An element's reactivity is determined by the number of electrons in the outer shell of its atom.
- To be perfectly stable, an atom requires a full outer shell of electrons.
- The inner shell of every atom can hold only two electrons - as the shells move further away from the nucleus, they can accommodate more electrons.
- Potassium, with a single outer shell electron, will react with other elements to leave it with a full outer shell.