Which rays are not the portion of em waves?

Options

A. X-rays
B. Microwaves
C. `alpha`-rays
D. Radio-waves

Explanation

To determine which rays are not part of electromagnetic (EM) waves, we need to understand the characteristics of EM waves and the types of radiation included in the electromagnetic spectrum.

### Step-by-Step Solution:

1. **Understanding Electromagnetic Waves**:
- Electromagnetic waves consist of oscillating electric and magnetic fields that propagate through space. These fields oscillate perpendicular to each other and to the direction of wave propagation.

2. **Identifying the Types of EM Waves**:
- The electromagnetic spectrum includes various types of waves, such as gamma rays, X-rays, ultraviolet (UV) light, visible light, infrared light, microwaves, and radio waves. All these waves are characterized by their frequency and wavelength.

3. **Distinguishing Between EM Waves and Other Rays**:
- While gamma rays, X-rays, UV light, visible light, infrared light, microwaves, and radio waves are all part of the electromagnetic spectrum, not all rays are EM waves.

4. **Identifying Non-EM Rays**:
- Alpha rays are not electromagnetic waves. Alpha rays are actually high-speed helium nuclei, which are particles and not waves. They do not exhibit the oscillating electric and magnetic fields characteristic of EM waves.

5. **Conclusion**:
- Therefore, the rays that are not part of electromagnetic waves include alpha rays (and other particle radiation such as beta rays and neutron radiation).

### Final Answer:
Alpha rays are not a portion of electromagnetic waves.

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