`BaTi[Si_(3)O_(9)]` is a class of

Options

A. orthosilicate
B. cyclic silicate
C. chain silicate
D. sheet silicate

Answer

To determine the class of the compound `BaTi[Si_(3)O_(9)]`, we can follow these steps:

### Step 1: Identify the Composition
The given compound is `BaTi[Si_(3)O_(9)]`. It consists of barium (Ba), titanium (Ti), and silicon (Si) along with oxygen (O). The presence of silicon and oxygen suggests that it is a silicate compound.

**Hint:** Look for the elements present in the compound to understand its classification.

### Step 2: Analyze the Silicon-Oxygen Framework
In silicate compounds, the arrangement of silicon (Si) and oxygen (O) can vary. The key arrangements are:
- **Ortho-silicates:** Discrete SiO₄⁴⁻ tetrahedra.
- **Chain-silicates:** Tetrahedra linked at corners to form chains.
- **Cyclic-silicates:** Tetrahedra linked to form closed rings.
- **Sheet-silicates:** Tetrahedra sharing three oxygen atoms to form two-dimensional sheets.

**Hint:** Identify how the silicon tetrahedra are arranged in the compound.

### Step 3: Determine the Arrangement in `BaTi[Si_(3)O_(9)]`
In `BaTi[Si_(3)O_(9)]`, the formula indicates that there are three silicon atoms and nine oxygen atoms. The arrangement suggests that these silicon tetrahedra are linked in a cyclic manner, forming a ring structure.

**Hint:** Count the number of silicon tetrahedra and how they are connected.

### Step 4: Classify the Compound
Since the silicon tetrahedra in `BaTi[Si_(3)O_(9)]` are arranged in a cyclic manner, this compound is classified as a cyclic-silicate. The specific name for this mineral is Benitoite, which is known for its cyclic silicate structure.

**Hint:** Recall the definitions of different silicate classes to confirm your classification.

### Conclusion
The compound `BaTi[Si_(3)O_(9)]` is classified as a **cyclic-silicate**.

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