Answer:
What is the only letter in the alphabet that does not appear anywhere on the periodic table of elements?
What comes once in a minute, twice in a moment, but never in a thousand years?
Not a burden for its weight and daily carried out, He who takes it wishes it had never come about
I'm not man's best friend, I'm their enemy, I can mark your end, yet you do not see me, I am very small, but very tough, If you have me, then you have it rough.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
When is it bad luck to see a black cat?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?