if a metal X is dropped in water it forms a silvery ball and deposits in the water and catchs a yellow flame. And the gas is also evolved. What is the metal and what is the gas evolved?

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Solution

Potassium is silvery white solid. When it is added to water, KOH and H₂ are formed. But the reaction is exothermic in nature. The heat evolved cause hydrogen to catches fire and produces water.
2K + 2H₂O → 2KOH + H₂+ heat
2H₂+ O₂ → 2H₂O

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if a metal X is dropped in water it forms a silvery ball and deposits in the water and catchs a yellow flame. And the gas is also evolved. What is the metal and what is the gas evolved?

Potassium is silvery white solid. When it is added to water, KOH and H2 are formed. But the reaction is exothermic in nature. The heat evolved cause hydrogen to catches fire and produces water. 2K + 2H2O → 2KOH + H2 + heat 2H2 + O2 → 2H2O

Potassium is silvery white solid. When it is added to water, KOH and H₂ are formed. But the reaction is exothermic in nature. The heat evolved cause hydrogen to catches fire and produces water.
2K + 2H₂O → 2KOH + H₂+ heat
2H₂+ O₂ → 2H₂O