Which of the following salts will produce a green flame on a $Pt$ wire?

When substance $A$ reacts with water,it produces a combustible gas $B$ and a solution of substance $C$ in water. When another substance $D$ reacts with solution $C$,it produces the same gas $B$,even when reacting with dilute sulfuric acid at room temperature. $A$ gives a golden yellow flame in a Bunsen burner flame. What are $A, B, C,$ and $D$ respectively?

Excess of $Na^{+}$ ions in our system causes:

Lithium aluminium hydride can be prepared from the reaction of

Fluorosis disease is caused due to the reaction of ...... with excess of fluoride in the body.

Carnallite in water dissociates to give $.....$ ions.