To which group do the following elements belong? Which of them has the highest metallic character?
$K, Na, Li, Rb$

The valence shell electronic configuration of alkali metals is

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

When magnesium burns in air,the compounds of magnesium formed are magnesium oxide and

Which of the following elements has the highest reaction rate with water?

Why do the alkali metals and their salts impart a characteristic color to an oxidizing flame?