What is the approximate velocity of a radio wave in free space?

Radio waves are a form of electromagnetic radiation, just like visible light. In a vacuum (or free space), all electromagnetic waves travel at the speed of light, which is approximately 300,000,000 meters per second (often written as 3 x 10^8 m/s). When looking at the options, pay close attention to the units. A common distractor uses "miles per hour" instead of "meters per second." The correct scientific constant is always measured in meters per second in this context.