`Ca_(3)(PO_(4))_(2)` is :

Answer

To solve the question regarding the compound \( \text{Ca}_3(\text{PO}_4)_2 \), we will analyze its composition and identify its common name.

### Step 1: Identify the components of the compound
The formula \( \text{Ca}_3(\text{PO}_4)_2 \) indicates that the compound contains calcium (Ca) and phosphate (PO₄) groups.

### Step 2: Determine the number of calcium and phosphate ions
From the formula:
- There are 3 calcium ions (Ca²⁺).
- There are 2 phosphate ions (PO₄³⁻).

### Step 3: Name the compound
The name of the compound \( \text{Ca}_3(\text{PO}_4)_2 \) is derived from its components:
- Calcium ions contribute to the name "calcium".
- The phosphate group contributes "phosphate".

Thus, the compound is called **calcium phosphate**.

### Step 4: Identify the specific type of calcium phosphate
Calcium phosphate can exist in various forms, but the specific form represented by \( \text{Ca}_3(\text{PO}_4)_2 \) is commonly known as **tricalcium phosphate**.

### Final Answer
Therefore, \( \text{Ca}_3(\text{PO}_4)_2 \) is known as **tricalcium phosphate** or **calcium phosphate**.

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