X ana Y are gases at room temperature. X is less reactive and is used to preserve food material, while 'Y' is required for combustion. Metal 'M' gets corroded when it combines with 'Y' in the presence of 'Z'. An atom of 'M' possess 14 electrons in the second last shell and N is the last shell. Identify X, Y, Z and M.

Explanation

14 electrons in the M shell and 2 electrons in the N shell correspond to the metal .Fe.. X is nitrogen which is filled in air tight food packets to prevent oxidation and Y is oxygen which is required for combustion. In presence of oxygen and water vapour (Z) metal iron (M) gets rusted to form a compound, i.e., `Fe_2O_3. XH_2O`. X = nitrogen Y = oxygen, Z = water vapour and M = Fe.