Spin isomerism is shown by

Hydrogen gains an electron to achieve the configuration of a noble gas. It behaves like which of the following?

$NaH$ is an example of:

How do ortho and para hydrogen differ from each other?

In which of the following reactions,hydrogen is acting as an oxidising agent?

Which of the following statements are $NOT$ correct?
$A$. Hydrogen is used to reduce heavy metal oxides to metals.
$B$. Heavy water is used to study reaction mechanism.
$C$. Hydrogen is used to make saturated fats from oils.
$D$. The $H-H$ bond dissociation enthalpy is lowest as compared to a single bond between two atoms of any elements.
$E$. Hydrogen reduces oxides of metals that are more active than iron.
Choose the most appropriate answer from the options given below: