Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
Alkali Metals are in the first Column of the Periodic Table. They are highly reactive with other kinds of elements like Hydrogen and Oxygen. Most of these elements are very rare like Francium, there is only 20 to 30 grams of it on earth. Some of them also melt very close to room temperature. But some are very common like Sodium and Potassium are found inside the body.