To complete Julie's chart comparing electromagnetic waves and sound waves, the best word to fill in the blank in the "Can travel ________" section would be "in a vacuum."
Here’s how the completed chart would look:
| Electromagnetic | Sound | |------------------------|-------------------------| | Are transverse | | | Are longitudinal | | | Can travel in a vacuum | | | Need a medium to travel through | Yes | | Fastest without a medium | Yes | | Fastest in a dense medium | No |
Electromagnetic waves can travel through a vacuum (as they do not require a medium), while sound waves require a medium (such as air, water, or solids) to propagate.