How will you distinguish between
(i) magnesium and calcium (ii) `Na_(2)SO_(4)` and `BaSO_(4)`

Explanation

To distinguish between magnesium and calcium, and between sodium sulfate and barium sulfate, we can follow these steps:

### Distinguishing Between Magnesium and Calcium

1. **Observation of Flame Test**:
- Heat a small sample of magnesium in a flame.
- Observe the color of the flame produced.
- **Result**: Magnesium does not produce a characteristic flame color due to its electrons being strongly bound to the nucleus.
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