What is so fragile that saying its name breaks it?

What is the riddle which can be asked all day with a different correct answer each time.

Take one out and scratch my head, I am now black but once was red. What am I?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

Count the squares in the matchstick puzzle below?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

In the figure, you can see nine stars. What you have to do is connect all of them by using just four line and without lifting your hand i.e. in a continuous flow.

How high do you have to count before you use the letter “a” in the English spelling of the whole number?