Answer:
The sharp slim blade, that cuts the wind.
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around.
What can be swallowed, but can swallow you?
What is the only letter in the alphabet that does not appear anywhere on the periodic table of elements?
What is it that makes tears without sorrow and takes its journey to heaven?
I always have to work with something in my eye. What am I?