First, let's start which varies. Things that will vary include the distribution of electrons between atoms, lone pairs, and bonds, the number of single vs double or triple bonds, and the formal charges on atoms in the structure.
What features do all the resonance forms of a molecules or ion have in common? Choose all that apply.
a) arrangement of electrons
b) formal charge on each atom
c) net charge on the molecule or ion
d) arrangment of atoms
e) none of these are common between resonance forms
f) atoms present
g) number of electrons