Which of the following correctly lists electromagnetic waves in order from longest to shortest wavelength ?

Options

A. Gamma rays, Ultraviolet, Infra-red, Microwaves.
B. Microwaves, Ultraviolet, Visible light, Gamma rays.
C. Radio waves, Infra-red, Gamma rays, Ultraviolet.
D. Radio waves, Infra-red, Visible light, X-rays.

Explanation

To solve the question of ordering electromagnetic waves from longest to shortest wavelength, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Electromagnetic Spectrum**:
The electromagnetic spectrum is a range of all the different frequencies of electromagnetic radiation. It includes various types of waves, each with a specific wavelength and frequency.

2. **List the Types of Electromagnetic Waves**:
The common types of electromagnetic waves, in order of decreasing wavelength (or increasing frequency), are:
- Radio Waves
- Microwaves
- Infrared Rays
- Visible Light (Red, Orange, Yellow, Green, Blue, Indigo, Violet)
- Ultraviolet Rays
- X-rays
- Gamma Rays

3. **Identify the Order from Longest to Shortest Wavelength**:
Based on the list above, the order from longest to shortest wavelength is:
- Radio Waves (Longest)
- Microwaves
- Infrared Rays
- Visible Light
- Ultraviolet Rays
- X-rays
- Gamma Rays (Shortest)

4. **Analyze the Given Options**:
The question provides several options for the order of these waves. We need to check which option correctly reflects the order established in the previous step.

5. **Select the Correct Option**:
After analyzing the options based on the established order:
- The correct order from longest to shortest wavelength is:
1. Radio Waves
2. Microwaves
3. Infrared Rays
4. Visible Light
5. Ultraviolet Rays
6. X-rays
7. Gamma Rays

Therefore, the option that matches this order is the correct answer.

### Conclusion:
The correct answer is the option that lists the waves in the order of Radio Waves, Microwaves, Infrared Rays, Visible Light, Ultraviolet Rays, X-rays, and Gamma Rays.

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