Final answer:
Electromagnetic waves can travel through a vacuum, which is a unique property compared to mechanical waves that require a medium. They always move at the speed of light in a vacuum, approximately 2.998 x 10⁸ m/s.
Step-by-step explanation:
Electromagnetic waves differ from other types of waves primarily because they are able to travel through a vacuum. Unlike mechanical waves such as sound that require a medium (air, water, or solids) to travel, electromagnetic waves can propagate through empty space. This ability is attributed to the nature of electromagnetic waves, which are oscillations of electric and magnetic fields that can exist independently of a medium. The speed of these waves is universally constant in a vacuum, marked by the speed of light c, which is approximately 2.998 × 10⁸ m/s. This characterizes one of the fundamental differences between electromagnetic waves, like light and radio waves, and other wave forms such as sound or water waves. Option B is correct .