When steam is passed over red hot iron,the substances formed are

Pure dihydrogen $(99.95\%)$ is obtained by the electrolysis of

At $298.2 \ K$,the relationship between the enthalpy of bond dissociation (in $kJ \ mol^{-1}$) for hydrogen $(E_{H})$ and its isotope,deuterium $(E_{D})$,is best described by:

Deuterium resembles hydrogen in properties but:

Heavy water is:

In which of the following reactions does hydrogen act as an oxidizing agent?