Answer:
I am lighter than air, but a hundred people cannot lift me. Careful, I am fragile. What am I?
A hole in a pole. Though I fill a hole in white I'm used more by the day and less by the night
In a tunnel of darkness lies a beast or iron. It can only attack when pulled back. What is it?
Sometimes dark and sometimes bright, I make my way among twinkling lights. Seas and oceans obey my call, yet mountains I cannot move at all. What am I?
I have a head tail but no arms and legs.
Born in the ocean and white as snow. When I fall back to water I disappear without a trace.