A piece of lithium metal is added to a beaker that contains water and phenolphthalein. Using what you know about the properties of bases, choose the best explanation for what you observe.

Lithium reacts with water to form lithium hydroxide and hydrogen gas: 2Li + 2H₂O → 2LiOH + H₂. Lithium hydroxide is a base, making the solution basic. Phenolphthalein turns pink in a basic solution, so the pink color indicates that a base is forming.

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