(a) It burns in oxygen with a dazzling white flame
(b) It reacts with cold water to form magnesium oxide and evolves hydrogen gas
(c) It reacts with hot water to form magnesium hydroxide and evolves hydrogen gas
(d) It reacts with steam to form magnesium hydroxide and evolves hydrogen gas
Answer: (b) It reacts with cold water to form magnesium oxide and evolves hydrogen gas
Reason: Magnesium does not react with cold water. It reacts only with hot water or steam to make its hydroxide and hydrogen gas convert.