During which month do people sleep the least?

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

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

Can you replace the question mark with the correct number in the below table sequence?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

It is always ahead of me yet I can never see it. What is it?

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

Cristina was born in 1888. She just had her 30th birthday today how did that happen?