Hydrogen has higher ionization energy than alkali metals,due to its

Which of the following is an electron-precise type of hydride?

$BF_3$ reacts with $NaH$ at $450 \ K$ to form $NaF$ and $X$. When $X$ reacts with $LiH$ in diethyl ether,$Y$ is formed. What is $Y$?

Which of the following is an ionic hydride?

Match the following:

List-$I$	List-$II$
$A$. Electron-deficient hydride	$I$. $CH_4$
$B$. Electron-precise hydride	$II$. $B_2H_6$
$C$. Electron-rich hydride	$III$. $CaH_2$
$D$. Saline hydride	$IV$. $NiH_{0.6}$
	$V$. $PH_3$

Name the classes of hydrides to which $H_2O$,$B_2H_6$ and $NaH$ belong.