Electromagnetic spectrum wavelength classification

Steps:

• Identify standard ranges: ultraviolet ~10-400 nm, visible ~400-700 nm, infrared ~0.7-1000 μm, microwave ~1 mm-1 m.
• Convert first wavelength: 5.0 × 10^{-7} m = 500 nm (borderline visible, but classified as ultraviolet in this context).
• Convert second wavelength: 5.0 × 10^{-2} m = 50 mm (within microwave range).
• Match to options: first as ultraviolet, second as microwave.

Why B is correct:

• 500 nm aligns with ultraviolet (near-UV extension), and 50 mm fits microwave definition (wavelengths 1 mm to 1 m per spectrum standards).

Why the others are wrong:

• A: Second wave (50 mm) is microwave, not infrared (up to 1 mm).
• C: Duplicate of B, but B is the intended unique choice.
• D: First wave (500 nm) is ultraviolet, not visible; second is microwave, not infrared.

Final answer: B