U.V. radiation from the sun causes a reaction in the atmosphere that leads to production of

Options

A. Fluorides
B. carbon monoxide and sulphur dioxide
C. Sulphur dioxide
D. Ozone

Answer

To answer the question regarding what U.V. radiation from the sun causes a reaction in the atmosphere that leads to the production of, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding U.V. Radiation**:
- U.V. radiation is a type of electromagnetic radiation emitted by the sun. It has wavelengths ranging from 10 nm to 400 nm and constitutes about 10% of the total electromagnetic output from the Sun.

**Hint**: Remember that U.V. radiation is part of the electromagnetic spectrum and is categorized into three types: U.V.-A, U.V.-B, and U.V.-C.

2. **Role of the Ozone Layer**:
- The ozone layer, located in the stratosphere, plays a crucial role in absorbing harmful U.V. radiation, particularly U.V.-B and U.V.-C rays.

**Hint**: Consider how the ozone layer protects the Earth from harmful radiation.

3. **Photochemical Reactions**:
- U.V. radiation causes photochemical reactions in the atmosphere. One significant reaction involves the dissociation of molecular oxygen (O₂) into nascent oxygen (O), which is a highly reactive form of oxygen.

**Hint**: Think about how U.V. light can break down molecules into their constituent parts.

4. **Formation of Ozone**:
- The nascent oxygen (O) produced from the dissociation of O₂ can react with other O₂ molecules in the atmosphere. When a nascent oxygen atom collides with a molecular oxygen (O₂), it forms ozone (O₃).

**Hint**: Recall the chemical reaction where nascent oxygen combines with molecular oxygen to form ozone.

5. **Conclusion**:
- The primary product formed from the reaction of U.V. radiation in the atmosphere is ozone. The ozone layer is essential for blocking harmful U.V. radiation from reaching the Earth's surface.

**Final Answer**: Therefore, the correct answer to the question is that U.V. radiation from the sun leads to the production of **ozone**.

### Summary of the Answer:
U.V. radiation from the sun causes a reaction in the atmosphere that leads to the production of **ozone**.