there both the same because blank paper is thicker but on the other hand lined paper has ink which makes it heavier as it is thinner...
Yes
it is a compound as it is more than one element and it is still chemicaly joined
Cats weigh around 8-10 pounds on average. So yes, they weigh more than 150 paper clips.
No!
SAME
No they would both weigh one pound. However, the paper would likely have a higher density.
In order to determine the actual weight of a 4X6 picture, the type of paper used to print the picture is needed. Glossy paper will weigh more than regular printing paper.
more than 9 pieces
You need more information. You need to know how much paper you are dealing with (a ream, or some other sheet count) and also the specific grade of paper. Reams of different paper can weigh differently.
Paper bags on average hold more weight then plastic bags
A little bit less than a train made out of paper, but way more than a boat made out of paper. Of course, the size of the airplane wasn't stated in the question. If it was a really, really BIG paper airplane, it could weigh more than a teeny-tiny paper train. Although, if it was a tiny paper airplane it could weigh less than a HUGE paper boat. I'm pretty sure it would also depend on what kind of paper you use. A construction paper airplane would definitely weigh more than a tissue paper airplane. But one of those airplanes made out of copier paper would weigh about average. I wouldn't reccommend a toilet paper airplane. It would also depend on what kind of plane you were making out of paper. A 747 made out of tar paper is going to completely outweigh a Cessna made out of freezer paper. All in all, I would have to say a medium sized airplane made out of a mid-gauge paper would weigh in at around 3,982 kilograms.
A paper airplane? A 747? Cessna?
They both weigh the same - one pound