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EleE03 Reaction of the metallic elements Ca and Mg with water

Calcium (Ca) is usually covered by a white layer.
* Left: The shining pure substances were uncovered by sandpaper.
* The two metal samples are placed in a 3-ml vial with water.
* Middle:  Only tiny bubbles are formed on magnesium (right),  the reaction of  calcium is violent:
                  the metal desintegrates, a white milky and big gasbubbles can be seen.
* Right: A white solid substance deposits, while magnesium remains unchanged.