On treatment with cold water, an element `(A)` reacted quietly liberating a colourless, odourless gas `(B)` and a basic solution `(C )`. Lithium reacted with `(B)` yielding a solid product `(D)` which effervesced with water to give a stongly basic solution `(E)` and gas `(F)`. When `CO_(2)` was bubbled through solution `(C )`, initially a white ppt. `(G)` was formed, but this redissolved forming solution `(H)` when more `CO_(2)` was passed, precipitate `(G)` effervesced when moistened with conc `HCl` and gave a brick red colouration to the bunsen flame. When `(G)` was heated with carbon at `1000^(@)C`, a caustic white compound `(I)` was formed, which when heated with `N_(20` at `1000^(@)C` gave a solid `(J)` of some commercial importance. Identify `(A)` to `(J)` and explain the reactions.

Explanation

To solve the question step by step, we will identify each element and compound from (A) to (J) based on the reactions described.

### Step 1: Identify Element (A)
- **Observation**: The element (A) reacts quietly with cold water, liberating a colorless, odorless gas (B) and a basic solution (C).
- **Conclusion**: The element that reacts quietly with cold water is Calcium (Ca). The reaction is:
\[ \text{Ca} + 2\text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{H}_2 \uparrow \]
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