The formation of soot particles during burning of a candle is due to

Options

A. burning of hydrogen
B. unburnt carbon particles left behind because of insufficient oxygen for burning
C. burning of hydrocarbons
D. all of these.

Explanation

To solve the question regarding the formation of soot particles during the burning of a candle, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Combustion**:
- When a candle burns, it undergoes a chemical reaction known as combustion. This process involves the candle wax (which is primarily made of hydrocarbons) reacting with oxygen in the air.

**Hint**: Recall that combustion is a reaction that typically requires oxygen.

2. **Role of Oxygen**:
- For complete combustion to occur, there must be a sufficient supply of oxygen. In complete combustion, hydrocarbons react with oxygen to produce carbon dioxide and water.

**Hint**: Think about what happens when there is enough oxygen for a reaction to proceed fully.

3. **Insufficient Oxygen**:
- If there is not enough oxygen available during the burning of the candle, the combustion process becomes incomplete. This means that not all of the carbon in the wax can convert to carbon dioxide.

**Hint**: Consider what might happen to the byproducts of combustion when oxygen levels are low.

4. **Formation of Soot**:
- The incomplete combustion of the hydrocarbons leads to the formation of soot, which consists of unburned carbon particles. These particles appear as black soot and are a result of the insufficient oxygen that prevents complete burning.

**Hint**: Remember that soot is a visible indication of incomplete combustion.

5. **Conclusion**:
- Therefore, the formation of soot particles during the burning of a candle is primarily due to the insufficient supply of oxygen, which leads to incomplete combustion of the candle wax.

**Final Answer**: The formation of soot particles during the burning of a candle is due to insufficient oxygen for complete combustion.

### Summary:
The soot particles are formed because of incomplete combustion resulting from a lack of oxygen, leading to the presence of unburned carbon.