Which of the following metals reacts explosively with cold water?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Potassium.
Alkali metals typically exhibit greater reactivity compared to other metals. Consequently, when an alkali metal comes into contact with cold water, it reacts vigorously, generating hydrogen gas. Metals like potassium and sodium react particularly violently with cold water, leading to an exothermic reaction where the evolved hydrogen quickly ignites, often causing small explosions accompanied by a distinctive popping sound. The reactivity sequence with water follows the order: K > Na > Ca > Mg, and so forth.