Answer:
I am a word. I become longer when the third letter is removed.
I make a loud sound when I'm changing. When I do change I get bigger but weigh less. What am I?
When I point up, it's bright. When I point down, it's dark. What am I?
Of the king I am blue and of the peasant I am red. Of the frog I am cold and of the dog I am hot instead. What am I?
By Moon or by Sun, I shall be found. Yet, if there's no light around, I am undone. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?