Write correctly balanced equation for the following 'word equation' :

calcium + water ⟶ calcium hydroxide + hydrogen

When steam is passed over red-hot iron, magnetic oxide of iron and hydrogen are obtained. 'The reaction between steam and red-hot iron is a Reversible Reaction'. What is meant by this statement.

Write balanced equation for the following reaction : magnesium + dil. hydrochloric acid ⟶

Name a gas which burns in air or oxygen forming water.