What is the total number of reasonable resonance contributors (including the one provided below) that can be drawn for ozone? reasonable resonance contributors will generally not have more than one formal charge per atom and will not violate the "octet" rule for any atom.

a = 1
b = 2
c = 3
d = 4

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.