Which of the following metal is not found in free state?
- A. Na
- B. Au
- C. Ag
- D. Pb
Answer: A. Na
- Sodium (Na) is a highly reactive alkali metal. It readily reacts with water, oxygen, and other elements in its environment. Therefore, it is never found in its pure metallic form naturally. Sodium highly reactive so kept under kerosene.
- Gold (Au), silver (Ag), and lead (Pb) are all less reactive metals compared to sodium. They are often found in their native state, meaning they can occur as free elements in nature.
Therefore, the correct answer is A. Na.