Simple riddles for teens with simple answers

Until I am measured I am not known. Yet how you miss me when I have flown.

What is as big as you are and yet does not weigh anything?

This word is a favorite of girls. Boys are unnerved on the mention of it. Once love finds its accompaniment, it becomes a lifelong event. What is it?

When you have me more, you can see only less. What Am I?

I cannot be felt, seen or touched, yet I can be found in everybody. My existence is always in debate, yet I have my own style of music.

What you cannot hold it but it is yours?

It is greater than god, more evil than the devil, the poor have it, the rich need it, and if you eat it, you will die? What is it?

I have a face but no eyes, hands but no arms. What am I?

Red through and through, it has no mouth. But it eats many things; it fears water but not wind.

What is the largest number you can write with just 3 digits?