Which one of the alkaline earth metal carbonates is thermally the most stable?
$MgCO_{3}, CaCO_{3}, SrCO_{3}, BaCO_{3}$

Heating compound $(A)$ produces a colorless gas and a residue $(B)$ which dissolves in water. Passing excess $CO_2$ gas through the aqueous solution of $(B)$ yields compound $(C)$,which is obtained in solid state. Gently heating compound $(C)$ gives back the white solid $(A)$. What is compound $(A)$?

Which one of the following pairs does not impart colour to the flame?

What is the order of basic strength for the hydroxides of the following alkaline earth metals?

Which of the following statements is incorrect?

Powdered Beryllium burns in air to give