Which one of the following will not give a flame test?

Which of the following alkaline earth metals shows some properties similar to aluminium?

Which one of the following is the strongest base?

Which of the following is true regarding alkaline earth metals?

$CO_2$ is passed through lime water. Initially,the solution turns milky and then becomes clear upon continued bubbling of $CO_2$. The clear solution is due to the formation of:

The solubility of carbonates of alkaline earth metals decreases down the group due to: