Allotrope of phosphorus which is polymeric consisting of chains of `P_(4)` tetrahedral linked together is

Options

A. White phosphorus
B. Red phosphorus
C. Black phosphorus
D. Both 1 and 2

Answer

To solve the question regarding the allotrope of phosphorus that is polymeric and consists of chains of P4 tetrahedra linked together, we can follow these steps:

### Step 1: Understand the Allotropic Forms of Phosphorus
Phosphorus has several allotropes, the most common being:
- White phosphorus (P4)
- Red phosphorus
- Black phosphorus

### Step 2: Analyze White Phosphorus
White phosphorus exists as discrete P4 tetrahedra. Each phosphorus atom in the P4 unit is bonded to three other phosphorus atoms, forming a tetrahedral shape. However, white phosphorus does not form polymeric chains; it exists as individual P4 units.

**Hint:** White phosphorus is characterized by its P4 tetrahedral structure, which does not link to form chains.

### Step 3: Analyze Red Phosphorus
Red phosphorus is formed by heating white phosphorus in the absence of air. In red phosphorus, the P4 units are linked together in a polymeric structure through covalent bonds. This means that red phosphorus consists of chains of P4 tetrahedra connected to each other.

**Hint:** Red phosphorus is a polymeric form where P4 units are covalently bonded to create a continuous structure.

### Step 4: Analyze Black Phosphorus
Black phosphorus exists in layered structures and can be found in two forms: alpha and beta. It does not consist of polymeric chains of P4 tetrahedra but rather has a more complex layered arrangement.

**Hint:** Black phosphorus has a layered structure and does not form polymeric chains like red phosphorus.

### Step 5: Conclusion
Based on the analysis of the three allotropes, the allotrope of phosphorus that is polymeric and consists of chains of P4 tetrahedra linked together is **red phosphorus**.

**Final Answer:** Red phosphorus.