English: Potassium reacting violently with water. Hydrogen is formed that ignites with a lilac flame; the flame color owing to burning potassium vapor. Strongly alkaline potassium hydroxide is formed in solution, turning phenolphthalein indicator solution violet red.
{{Information |Description={{en|1=Potassium reacting violently with water. Hydrogen is formed that ignites with a lilac flame; the flame color owing to burning potassium vapor. Strongly alkaline potassium hydroxide is formed in solution, turning phenolpht