Difficult General Knowledge Quiz

The descriptions in the title, this is a proper general knowledge quiz, difficult but not impossible.

1 The square root of -1 is what?
2 Who wrote the Enigma Variations? The more correct detail, (the more points you recieve, any incorrect detail=no points)
3 Which Greek playwright is reputed to have died when an eagle dropped a tortoise on his head?
4 What is the mode of this data 1,1,2,3,3,4,4,4,5,7,8,8,8,8,9?
5 What is the Bootstrap Paradox?
6 Which of these is not a lepton or anti-lepton?
7 Who wrote the children's book Charlotte's Web?
8 What Name did Isaac Newton give to what we now call Calculus?
9 In what year did Queen Victoria of England come to the throne? (the closer you are, the more points you recieve)
10 Which of these is NOT a novel by the Bronte sisters?
11 What is the fastest fish in the world?
12 Which of these countries is NOT on the border of Austria?
13 Who is the chief god in Norse mythology?