A substance that is translucent waxy solid and shows chemiluminescence is:

Question

Accepted Answer

White phosphorus is the correct answer for the substance that is a translucent waxy solid and shows chemiluminescence. Here is a detailed explanation supporting this:

1. **White Phosphorus**:
   - **Physical Properties**: White phosphorus is known for being a translucent, waxy solid. It is typically stored underwater or in inert gases to prevent it from reacting with oxygen in the air.
   - **Chemiluminescence**: White phosphorus exhibits chemiluminescence, which means it emits light as a result of a chemical reaction. This occurs when white phosphorus is exposed to oxygen, causing it to glow in the dark. This property is unique among the different allotropes of phosphorus.

2. **Why the Other Options are Incorrect**:
   - **a-Black Phosphorus**: This allotrope of phosphorus is not waxy or translucent. Instead, it is a black, flaky solid that resembles graphite. It does not exhibit chemiluminescence.
   - **ß-Black Phosphorus**: Similar to a-black phosphorus, ß-black phosphorus is also a form of black phosphorus with a layered structure. It is not waxy or translucent and does not show chemiluminescence.
   - **Red Phosphorus**: Red phosphorus is a more stable allotrope compared to white phosphorus. It is a dark red powder or crystalline solid and does not exhibit the waxy, translucent properties or chemiluminescence that white phosphorus does.

In conclusion, white phosphorus is the only allotrope among the options provided that matches the description of being a translucent waxy solid and showing chemiluminescence, which is why Option 4 is the correct answer.