When we see 2 but call 10?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What has no start, end, or centre?

Why do people go to bed?

What is the fastest way to double your money?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

What 5-letter word typed in all capital letters can be read the same upside down?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

What kind of band never plays music?