List three ways light waves are different from sound waves.

There are a number of differences between light waves and sound waves and these are listed as follows:

• Light waves are electromagnetic waves, while sound waves are mechanical waves. 


• Light waves do not require a medium to travel, while sound waves cannot travel without a medium. This is how light can travel through space and we can see stars. In comparison, sound waves cannot travel through vacuum.  


• Light waves travel at a much higher velocity as compared to sound waves. The velocity of light waves (through a vacuum) is `3 xx 10^8` m/s. In comparison, the velocity of sound waves (in air) is about 343 m/s. 


• Different frequencies of light waves give rise to different colors. On the other hand, different frequencies of sound waves result in different pitches. Light waves and sound waves have very different frequencies from each other. Sound waves have low frequencies (20 to 20,000 Hz) as compared to light waves (~ `10^14`  Hz).

Hope this helps.