That depends on how big it is.
yes.
Enough room that you can see them
about 6 cm by 10cm
It won't, Magnesium won't blow up.
one hundred wind turbines take up one kilometre of land
about half a a humans normal room
Titanic was 882 ft. long.
A Bose Subwoofer does not take up too much room. The average size of a Bose Subwoofer is about 6 inches by 9 inches. However, there is another model that is 8 inches round.
Yes, apps take up memory and space on your iPod.
Air does indeed take up room. Air molecules have a mass that takes up whatever room it is confined to.
It depends on the size of the cage. They will take a bit of space but not so much that you will get annoyed with it. Maybe about half/a quarter of a room or so.
because they need room for the particles to move around