The most soluble bicarbonate is

Which of the following sets represents the alkali metals?

The electronic configuration of $Cs$ is

$A$ metal $(A)$ on heating in nitrogen gas gives compound $(B)$. $(B)$ on treatment with $H_{2}O$ gives a colourless gas which when passed through $CuSO_{4}$ solution gives a dark blue-violet coloured solution. $(A)$ and $(B)$ respectively,are

Which of the following statements is correct regarding the solubility of carbonates?

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