The alkali metals are six elements grouped together on the periodic table because they have similar properties, such as being soft metals and having one electron in their outermost energy levels. This group consists of the elements lithium, sodium, potassium, rubidium, cesium, and francium.
Alkali metals are electron donors, meaning they tend to give away their single electrons to other atoms to form more stable configurations. They form compounds readily and cannot be found in their pure state in nature. Alkali metals are usually kept protected from air because they react easily with elements present in the air such as oxygen and water vapor. These active elements like to form compounds with the halogen group, which readily accept an alkali metal's single donated electron.