19Group 1 Group 2 MetalsMedium1 markWhen hydrated magnesium nitrate, Mg(NO3)2⋅7H2O, is heated, which three gases are given off?Anitrogen(II) oxide, oxygen and water vapourBhydrogen, nitrogen and oxygenChydrogen, nitrogen(IV) oxide and oxygenDnitrogen(IV) oxide, oxygen and water vapourGrade answerSolutionGrading criteria