Which of the following is / are not electromagnetic wave?

Options

A. Gamma rays
B. Alpha rays
C. Beta rays
D. X- rays

Explanation

To determine which of the following options are not electromagnetic waves, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Electromagnetic Waves**:
- Electromagnetic waves are waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity. They include gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves.

2. **Analyzing Gamma Rays**:
- Gamma rays are high-energy photons emitted from radioactive decay. They are part of the electromagnetic spectrum.
- **Conclusion**: Gamma rays are electromagnetic waves.

3. **Analyzing Alpha Rays**:
- Alpha rays consist of alpha particles, which are helium nuclei (two protons and two neutrons). They are not waves but rather particles.
- **Conclusion**: Alpha rays are not electromagnetic waves.

4. **Analyzing Beta Rays**:
- Beta rays are composed of beta particles, which are electrons or positrons. Like alpha rays, they are also particles and not waves.
- **Conclusion**: Beta rays are not electromagnetic waves.

5. **Analyzing X-Rays**:
- X-rays are a form of electromagnetic radiation with high frequency and energy. They are used in medical imaging and are part of the electromagnetic spectrum.
- **Conclusion**: X-rays are electromagnetic waves.

### Final Answer:
The options that are not electromagnetic waves are **Alpha rays and Beta rays**.