The compound (s) which generate (s) `N_(2)` upon thermal decomposation is (are) :

Options

A. `NH_(4)NO_(3)`
B. `(NH_(4))_(2) Cr_(2)O_(7)`
C. `Ba(N_(3))_(2)`
D. `Mg_(3)N_(2)`

Answer

To determine which compounds generate nitrogen gas (N₂) upon thermal decomposition, we will analyze the given compounds one by one.

### Step 1: Analyze Ammonium Nitrate (NH₄NO₃)
- **Decomposition Reaction**: When ammonium nitrate is heated, it decomposes to form nitrous oxide (N₂O) and water (H₂O).
- **Result**: No nitrogen gas (N₂) is produced.

### Step 2: Analyze Ammonium Dichromate (NH₄)₂Cr₂O₇
- **Decomposition Reaction**: Upon heating, ammonium dichromate decomposes to produce chromium(III) oxide (Cr₂O₃), nitrogen gas (N₂), and water (H₂O).
- **Result**: Nitrogen gas (N₂) is produced.

### Step 3: Analyze Barium Azide (Ba(N₃)₂)
- **Decomposition Reaction**: Barium azide decomposes upon heating to yield barium oxide (BaO) and nitrogen gas (N₂).
- **Result**: Nitrogen gas (N₂) is produced.

### Step 4: Analyze Magnesium Nitride (Mg₃N₂)
- **Decomposition Reaction**: Magnesium nitride decomposes upon heating to produce magnesium (Mg) and nitrogen gas (N₂).
- **Result**: Nitrogen gas (N₂) is produced.

### Conclusion
The compounds that generate nitrogen gas (N₂) upon thermal decomposition are:
1. Ammonium Dichromate (NH₄)₂Cr₂O₇
2. Barium Azide (Ba(N₃)₂)
3. Magnesium Nitride (Mg₃N₂)

Thus, the correct options are:
- (NH₄)₂Cr₂O₇
- Ba(N₃)₂
- Mg₃N₂

### Final Answer
The compounds which generate nitrogen gas upon thermal decomposition are:
- (NH₄)₂Cr₂O₇
- Ba(N₃)₂
- Mg₃N₂

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