Which one of the following will react most vigorously with water?

The elements of group $IA$ provide a colour to the flame of a Bunsen burner due to

Which of the following releases brown gas on heating?

The correct order of electrical conductivity of alkali metal ions in their aqueous solution for $Cs^{+}$, $K^{+}$, $Na^{+}$, and $Li^{+}$ is:

Why is $lithium$ superoxide $(LiO_2)$ not possible?

Magnitude of which of the following property of alkali metals increases with the increase of atomic number?