When compared to other types of waves, electromagnetic waves differ because they are

They differ because they are transverse wave. That is their direction of travel is perpendicular to its vibrations. I'm not that sure though. Hope you get it right :)

The purpose of a lab is to do your "expirements" the importance of the topic is so you can now what the story is about and the last one is because no one is me with my question ( what is 3 over 4 x - 9 = 27 maybe you can )