A sample of iodine is easiest to ship as a powder because it is making it easy to break into small pieces. Helium is less .
than the elements that make up the air we breathe, so a balloon filled with helium will float in air.

Plastic is a compound of nonmetallic elements, so its .
properties make it a popular coating for electric wires to prevent the current from escaping.
*ANSWERS
1): brittle.
2): dense.
3) electrically insulating.
I hope this helped your question! (All of these answers are correct by the way :>)