Ionosphere is mainly composed if

Options

A. electrons and positive ions
B. ozone gas
C. nitrogen and oxygen
D. b and c both

Answer

### Step-by-Step Solution:

1. **Understanding the Term "Ionosphere":**
- The term "ionosphere" can be broken down into two parts: "ion" and "sphere."
- "Ion" refers to charged particles, while "sphere" indicates a layer or region.

2. **Composition of the Ionosphere:**
- The ionosphere is a layer of the Earth's atmosphere that is ionized by solar and cosmic radiation.
- It contains a significant number of ions and free electrons.

3. **Types of Particles Present:**
- The ionosphere primarily consists of:
- **Electrons:** Negatively charged particles.
- **Positive Ions:** These can include various types of ions, such as hydrogen ions (H⁺) and other positive ions formed from different elements.

4. **Clarification on Protons:**
- It is important to note that protons do not exist freely in the ionosphere; they are typically found within atomic nuclei.
- Therefore, we refer to "positive ions" instead of protons.

5. **Final Answer:**
- The ionosphere is mainly composed of **electrons and positive ions**.

### Conclusion:
- Thus, the correct answer is that the ionosphere is mainly composed of **electrons and positive ions**.