Which of the following electromagnetic spectra has the shortest wavelength?

Analysis

The question asks you to identify which of the listed electromagnetic radiations has the shortest wavelength. To answer this, we must recall the electromagnetic spectrum and the relationship between wavelength, frequency, and energy.

Concept Explanation

The electromagnetic spectrum is a range of waves arranged in order of increasing frequency and decreasing wavelength. The general order from longest wavelength (lowest frequency) to shortest wavelength (highest frequency) is:

1. Radio waves (Longest wavelength)
2. Microwaves
3. Infrared
4. Visible light
5. Ultraviolet (UV)
6. X-rays
7. Gamma rays (Shortest wavelength)

Key Principle: Wavelength ($\lambda$) and frequency ($f$) are inversely proportional according to the formula $c = f\lambda$ (where $c$ is the speed of light). Therefore, as you move toward the high-energy end of the spectrum (X-rays and Gamma rays), the wavelength becomes significantly shorter.

Step-by-Step Solution

1. Compare the given options: • Infrared: Longer wavelength than visible light. • Visible light: Longer wavelength than UV. • Ultraviolet: Longer wavelength than X-rays. • X-rays: Located at the high-frequency end of this specific list.

2. Evaluate the positions: Looking at the spectrum order, X-rays appear after Ultraviolet and Visible light. Since wavelength decreases as we move from Infrared toward X-rays, X-rays must have the shortest wavelength among the options provided.

Conclusion

Comparing the options provided, X-rays have the highest frequency and, consequently, the shortest wavelength.

Exam Tip: Remember the mnemonic "Raging Martians Invaded Venus Using X-ray Guns" to recall the order of the spectrum:

• Radio
• Microwaves
• Infrared
• Visible
• Ultraviolet
• X-rays
• Gamma rays As you move from left to right, the wavelength gets shorter!