$A$ piece of magnesium ribbon is heated to redness in an atmosphere of nitrogen and on cooling with water,the evolved gas is

Alkali metal hydrides react with water to give:

$P \xrightarrow{\Delta } Q$ (metallic solid) $+ R \uparrow + S \uparrow$
$X \xrightarrow{\Delta } Y$ (amphoteric oxide) $+ R \uparrow + S \uparrow$
$P$ and $X$ are respectively:

Identify the correct statements about alkali metals.
$A$. The order of standard reduction potential $(M^{+} \mid M)$ for alkali metal ions is $Na > Rb > Li$.
$B$. $CsI$ is highly soluble in water.
$C$. Lithium carbonate is highly stable to heat.
$D$. Potassium dissolved in concentrated liquid ammonia is blue in colour and paramagnetic.
$E$. All the alkali metal hydrides are ionic solids.
Choose the correct answer from the options given below.

Match the following:

Compound	Molecular formula
$1$. Lime stone	$a$. $CaO$
$2$. Quick lime	$b$. $NaHCO_3$
$3$. Washing soda	$c$. $CaCO_3$
$4$. Baking soda	$d$. $Na_2CO_3 \cdot 10H_2O$

When $Zn$ is treated with excess of $NaOH$,the product obtained is