Here's why they're so reactive:
* One valence electron: They have only one electron in their outermost shell, which they readily lose to achieve a stable noble gas configuration.
* Low ionization energy: It takes very little energy to remove this single valence electron.
* Large atomic radius: Their large size means the valence electron is held loosely and is easily removed.
Examples of alkali metals:
* Lithium (Li)
* Sodium (Na)
* Potassium (K)
* Rubidium (Rb)
* Cesium (Cs)
* Francium (Fr)
These metals react vigorously with water, oxygen, and acids. They are so reactive that they are never found in their pure form in nature and must be stored in inert environments.
