I can change from solid to liquid and then to gas. I’m essential for life, yet I can be a nuisance. What am I?

Category: Science · Difficulty: medium

Hint: I’m often found in rivers, but I can also fill your glass.

Answer

Water

Explanation

Water is unique in that it exists in three states: solid (ice), liquid (water), and gas (steam), and is vital for all known forms of life.

This is a medium science riddle — a moderate challenge for most people. The answer is Water.

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