Which of the following is the least reactive element?

Correct option is A

The correct answer is (a) Neon.
· Neon is the least reactive element among the given options because it is a noble gas.
· Noble gases, such as neon, have a complete outer electron shell, making them chemically stable and highly unreactive.
· They rarely form compounds with other elements because they do not need to gain, lose, or share electrons to achieve a stable configuration.
· In contrast, elements like chlorine, oxygen, and hydrogen are much more reactive because they do not have fully filled outer electron shells and tend to form bonds with other elements to achieve stability.
Information Booster:
· Chlorine (Group 17, halogens) is highly reactive and often forms compounds like sodium chloride (salt).
· Oxygen is reactive and essential for combustion and respiration, forming compounds with most elements.
· Hydrogen is reactive, especially in the presence of oxygen, and forms water and other compounds.