On passing electric current over molten ionic hydrides of $s-$block elements,

Write a short note on Ionic or Saline Hydrides.

Liquid ammonia is used in refrigeration because of its

Consider the following statements:
$1.$ Atomic hydrogen is obtained by passing hydrogen through an electric arc.
$2.$ Hydrogen gas will not reduce heated aluminium oxide.
$3.$ Finely divided palladium adsorbs large volume of hydrogen gas.
$4.$ Pure nascent hydrogen is best obtained by reacting $Na$ with $C_2H_5OH$.
Which of the above statements is/are correct?

The conversion of atomic hydrogen into ordinary hydrogen is:

Identify the correct composition of water gas from the following.