Complex sentence: They react vigorously with water to liberate hydrogen, except for magnesium, which reacts slowly, and beryllium, which reacts only when amalgamated with mercury to destroy the oxide film.lithium which has similar properties to magnesium due to the diagonal relationship with magnesium in the periodic table.
Split into simpler sentences: They react vigorously with water to liberate hydrogen, except for magnesium, which reacts slowly, and beryllium, which reacts only when amalgamated with mercury to destroy the oxide film. Lithium which has similar properties to magnesium due to the diagonal relationship with magnesium in the periodic table.