Given below are two statements.

Statement I : Pig iron is obtained by heating cast iron with scrap iron.

Statement II : Pig iron has a relatively lower carbon content than that of cast iron.

In the light of the above statements, choose the correct answer from the options given below.

High purity (> 99.95%) dihydrogen is obtained by :

The correct order of density is :

The total number of acidic oxides from the following list is

NO, N₂O, B₂O₃, N₂O₅, CO, SO₃, P₄O₁₀