Which of the following is the first alkali metal?

Correct option is A

The correct answer is (a) Lithium.
· Lithium (Li) is the first alkali metal in the periodic table. Alkali metals belong to Group 1 and are known for being highly reactive, especially with water.
· Lithium is the lightest alkali metal and is used in various applications, such as in batteries and as a treatment for bipolar disorder.
· Alkali Metals: Group 1 elements include Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr). They are characterized by having one electron in their outermost shell, making them highly reactive.
· Lithium is the first element in this group and the lightest metal, with atomic number 3.
Additional Information:
· Hydrogen: Though it is placed in Group 1, it is not considered an alkali metal. It is a non-metal.
· Francium: It is the heaviest and most radioactive alkali metal, rarely found in nature.
· Sodium (Na): The second alkali metal after Lithium, and more commonly known for its role in table salt (sodium chloride).