Tritium is the isotope of

Hydrogen combines with other elements by

The radioactive isotope of hydrogen is:

How does the atomic hydrogen or oxy-hydrogen torch function for cutting and welding purposes? Explain.

Write the physical properties of $H_2$.

Identify the reactions in which $H_2$ is liberated? $(i)$ $Zn + NaOH_{(aq)} \longrightarrow$ $(ii)$ $HCOOH \xrightarrow[\text{Conc. } H_2SO_4]{373 \ K}$ $(iii)$ $CH_{4(g)} + H_2O_{(g)} \xrightarrow[Ni]{1270 \ K}$ $(iv)$ $Zn + H^+_{(aq)} \longrightarrow$ $(v)$ $C_{(s)} + H_2O_{(g)} \xrightarrow{1270 \ K}$