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Which gas is produced when calcium reacts with water?

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A labeled diagram of the periodic table entry for calcium, showing its atomic number 20, symbol Ca, atomic weight 40.078, electron configuration, and classification as an alkaline-earth metal. Icons indicate calcium is a solid with a face-centered cubic crystal structure and strongly basic oxides at room temperature. — calcium The chemical element calcium is the most abundant metallic element in the human body.

When calcium reacts with water, it produces hydrogen gas and calcium hydroxide. The metal reacts rapidly with warm water and more slowly with cold water to facilitate this process.1