On heating,hydrazoic acid forms:

Which one of the following is the most abundant element in the universe?

The reaction of $H_2S$ with $O_2$ produces .....

Where is the position of hydrogen in the periodic table? Why?

The intermolecular force in solid hydrogen is .........

Which of the following statement$(s)$ is/are correct:
$A$. $NaH$ is a non-volatile hydride
$B$. $MgH_2$ is a polymeric hydride
$C$. $NH_3$ is an electron-precise hydride
$D$. $H_2O$ is an electron-rich hydride