The product obtained as a result of a reaction of nitrogen with $CaC_2$ is

As the atomic number increases,which of the following properties of alkali metals increases?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Lithium salts are hydrated.
Reason $(R):$ Lithium has higher polarising power than other alkali metal group members.
In the light of the above statements,choose the most appropriate answer from the options given below:

Characteristic feature of alkali metals is

Give points of similarities between lithium and magnesium.

Which one of the following nitrates will decompose to give $NO_2$ on heating?