The water gas on reacting with cobalt as a catalyst forms

Choose the incorrect statement for deuterium.

Dihydrogen of high purity $(>99.95 \%)$ is obtained through:

During the water-gas shift reaction:

Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Identify the correct statements from the following:
$(I)$ The formula of Calgon is $Na_6(PO_3)_6$.
$(II)$ Exhausted permutit is regenerated by aqueous $KCl$ solution.
$(III)$ Calcium stearate is soluble in water.
$(IV)$ In ice crystals,each oxygen is surrounded by four oxygen atoms.