Which isotope of hydrogen emits a $\beta-$particle?

Identify the correct statements from the following:
$i$. Reaction of hydrogen with fluorine occurs even in dark.
$ii$. Manufacture of ammonia by Haber process is an endothermic reaction.
$iii$. $HF$ is an electron-rich hydride.

Fire extinguishers contain $H_2SO_4$ and

Which of the following is the water-gas shift reaction?

The maximum sum of the number of neutrons and protons in an isotope of hydrogen is

Which statement is not correct for ortho and para hydrogen?